Weighing device

Abstract

An apparatus comprising: a measurement chamber having a removable cover; and a plurality of wafer support elements for supporting wafers from below, wherein the plurality of wafer support elements are provided on the cover.

Description

Technical Field

[0001] The present invention relates to a weighing device for measuring the weight of a wafer. Prior Art

[0002] Microelectronic devices are fabricated on semiconductor (e.g., silicon) wafers using a variety of techniques, including deposition techniques (e.g., CVD, PECVD, PVD) and removal techniques (e.g., chemical etching, CMP). Semiconductor wafers may be further processed in ways that alter their quality, such as through cleaning, ion implantation, lithography, and the like.

[0003] Depending on the device being manufactured, each semiconductor wafer may undergo hundreds of different processing steps in sequence to build and / or remove the layers and materials required for its final operation. In practice, each semiconductor wafer passes along a production line. The nature of semiconductor manufacturing means that certain processing steps or series of steps in the production flow may be repeated in a similar or identical manner. For example, this may be to build similar metal conductor layers to interconnect different parts of the active circuit.

[0004] To ensure consistency and interoperability among semiconductor equipment used in different fabs, most semiconductor manufacturing industries adopt standards. For example, the standards developed by the Semiconductor Equipment and Materials International (SEMI) have high market acceptance. An example of standardization is the size and shape of semiconductor (silicon) wafers: Typically, for mass production, they are discs with a diameter of 300 mm. However, some semiconductor (silicon) wafers (typically used in older fabs) are discs with a diameter of 200 mm.

[0005] The cost and complexity of the processing steps required to produce a complete silicon wafer, coupled with the time required to reach the end of the production line where its operation can be properly evaluated, has led to a desire to monitor the operation of the equipment in the production line and the quality of the wafers being processed throughout the process to ensure confidence in the performance and yield of the final wafer.

[0006] Wafer processing techniques often result in quality variations on or near the surface of semiconductor wafers. The configuration of these surface variations is often critical to device functionality, so wafers must be evaluated during production to determine if they possess the correct configuration for quality control purposes.

[0007] Specialized metrology tools can be used in the production process to enable monitoring immediately after the relevant process of interest and generally before any subsequent processing (i.e., between processing steps).

[0008] Measuring mass variations on either side of a wafer during processing steps is an attractive approach for production wafer metrology. It is relatively low-cost, rapid, and automatically adaptable to varying wafer circuit patterns. Furthermore, it often provides results with higher accuracy than alternative techniques. For example, for many typical materials, the thickness of a material layer can be resolved down to the atomic scale. The wafer in question is weighed before and after the processing step of interest. The mass variation is correlated with the performance of the production equipment and / or the desired characteristics of the wafer.

[0009] More accurate measurement of wafer quality variations enables tighter quality control of wafer processing.

[0010] WO / 2002 / 003449 discloses an apparatus and method for studying semiconductor wafers, wherein changes in wafer mass are measured to evaluate various wafer characteristics, enabling, for example, wafer manufacturing monitoring. A common method for obtaining mass measurements uses very sensitive force sensors to measure the force due to gravity (weight). With moderate accuracy, this force can be assumed to be solely due to the wafer's mass. However, if higher accuracy is required, other forces may need to be considered.

[0011] These forces, as disclosed in WO / 2002 / 003449, are generated by atmospheric buoyancy. In semiconductor measurement, semiconductor wafers are typically measured in atmospheric air (i.e., not in a vacuum). The wafer displaces a certain volume of this atmosphere, resulting in an upward thrust. This upward thrust depends on the atmospheric (air) density, which in turn depends on numerous factors, including temperature, pressure, relative humidity, and air composition. This upward force causes the apparent weight of the wafer, as detected by the force sensor, to decrease.

[0012] WO / 2002 / 003449 discloses a method for compensating for or correcting for the effects of atmospheric buoyancy. Sensors are provided to monitor temperature, pressure, and relative humidity. A processor receives these measurements from the sensors and uses them to calculate air density, which can be used to compensate for buoyancy in corresponding weight measurements. The processor calculates buoyancy based on the calculated air density, along with weight measurements and density information associated with the wafer. Summary of the Invention

[0013] The present inventors have learned that if the semiconductor wafer is not flat, for example, the wafer has a curved or bowed shape, or if the wafer is not supported during weight measurement so that it is horizontal or approximately horizontal (e.g., in a lateral or approximately lateral orientation), the weight measurement may be incorrect or inaccurate.

[0014] For example, if the semiconductor wafer is not supported so that it is horizontal or approximately horizontal (e.g., in a lateral or approximately lateral orientation) during weight measurement, there may be a significant deviation between the expected wafer edge position if the wafer were horizontal and the actual wafer edge position.

[0015] In practice, it is not uncommon for semiconductor wafers to be supported in a non-level or approximately non-level state during weight measurement.

[0016] For example, load cells can be used to perform weight measurements. When manufacturing these load cells, the configuration, position, and / or orientation of the load cell (and / or the housing surrounding the load cell) can be configured to achieve optimal performance. In this optimal configuration, the load cell (and / or the housing surrounding the load cell) is often not horizontal. In other words, the load cell's weighing axis or weighing direction (the direction in which the load cell measures weight) may not be vertical, and / or the top and / or bottom surfaces of the load cell (and / or the housing surrounding the load cell) may not be horizontal.

[0017] If the load cell is not level, a balance pan or weighing pan connected or coupled to the load cell and supporting the semiconductor wafer during weight measurement will also not be level, such that the wafer will not be supported so that it is horizontal or approximately horizontal (e.g., in a lateral or approximately lateral direction) during weight measurement.

[0018] The discrepancy between the expected wafer edge position when the wafer is level and the actual wafer edge position can cause a number of problems. For example, in some cases, the discrepancy can be sufficient to cause the wafer edge to contact a portion of a device or apparatus, such as a portion of the measurement chamber surrounding a weighing device performing weight measurements. This means that part of the wafer's weight may be supported by a portion of the device or apparatus, resulting in incorrect or inaccurate weight measurements of the wafer.

[0019] Additionally or alternatively, this deviation may change the distance between a portion of the wafer (e.g., the wafer edge) and a portion of a device or apparatus (e.g., a portion of a measurement chamber surrounding a weighing device performing weight measurements). In particular, the deviation may reduce the distance between the portion of the wafer and the portion of the apparatus or apparatus. This may increase electrostatic forces between the portion of the wafer and the portion of the apparatus or apparatus, which are caused by electrostatic charges on the wafer and / or on the portion of the apparatus or apparatus. These electrostatic forces acting on the wafer may alter the gravitational force measured during weight measurements, resulting in incorrect or inaccurate weight measurements of the wafer.

[0020] Additionally or alternatively, the load cell may be level, but the support (e.g., a balance pan or weighing pan) used to support the wafer during the weight measurement may not be level, for example, due to variations in the support's manufacturing. This may also result in the wafer not being supported so that it is level or approximately level (e.g., in a lateral or approximately lateral orientation) during the weight measurement.

[0021] Additionally or alternatively to the issues discussed above, the semiconductor wafer may not be flat. For example, the semiconductor wafer may have a curved or bowed shape.

[0022] This means that when the wafer is supported during weight measurement, there may be uncertainty about the location of the wafer edge. Consequently, there may be significant deviations between the expected wafer edge location when the wafer is flat and the actual wafer edge location. This deviation may also lead to one or more of the issues discussed above.

[0023] Aspects of the present invention may address one or more of these problems.

[0024] According to a first aspect of the present invention, a weighing device for measuring the weight of a wafer having a specific diameter D is provided, the weighing device including a support member for supporting the wafer during weight measurement, wherein: the support member includes a plurality of contact elements configured to contact the underside of the wafer at a distance less than or equal to D / 3 from the edge of the wafer to support the wafer during weight measurement.

[0025] According to a first aspect of the present invention, the wafer is supported from below closer to the edge of the wafer (eg, the outer circumferential edge or peripheral edge or radially outer edge) than in the previous embodiment.

[0026] This means that even if the wafer is not flat (eg, the wafer is curved or bowed), the position of the wafer edge can be better controlled and / or more clearly defined because the wafer is supported closer to the edge.

[0027] In contrast, if the wafer is supported closer to the center of the wafer than in the present invention, and the wafer is curved or bowed, there may be significant uncertainty regarding the location of the wafer edge, which may lead to one or more of the problems discussed above.

[0028] The weighing device according to the first aspect of the present invention may have any one or any combination of the following optional features (where compatible).

[0029] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0030] The wafer may have a disc shape.

[0031] Performing weight measurements on the wafer may include performing gravimetric measurements on the wafer.

[0032] Taking weight measurements of the wafer may include generating a measurement output indicative of the weight of the wafer.

[0033] The measurement output may include an electrical signal or an electric output corresponding to the measured weight. For example, the magnitude of the current or voltage of the electrical signal or the electric output may correspond to the measured weight.

[0034] Performing weight measurements on a wafer may include measuring the weight of the wafer, or measuring the difference between the weight of the wafer and the weight of another object, such as a reference mass or reference wafer.

[0035] Taking a weight measurement of the wafer may include measuring a difference between the weight of the wafer and a counterweight.

[0036] The weighing device may be configured to calculate information related to the quality of the wafer, such as the wafer mass or a change in the wafer mass, based at least on the weight measurement.

[0037] The weighing device may comprise or be a microbalance.

[0038] The weighing device may include or be a weighing scale.

[0039] The weighing device may include or be an electronic balance.

[0040] A weighing device may include a force sensor or load cell for generating a measurement output indicative of the weight of an object loaded on the weighing device.

[0041] A weighing device may include a gravity sensor or gravimetric transducer for generating a measurement output indicative of the weight of an object loaded on the weighing device.

[0042] The weighing device may include a load cell for generating a measurement output indicative of the weight of an object loaded on the weighing device.

[0043] The weighing device may include an electromagnetic force compensation or electromagnetic force restoring force sensor or a load cell.

[0044] The weighing device is used to measure the weight of a wafer having a specific diameter D. Specifically, the weighing device can be configured to or adapted to measure the weight of a wafer having a specific diameter D.

[0045] Typically, semiconductor wafer processing or metrology equipment is configured to process semiconductor wafers of a specific diameter, such as 200 mm or 300 mm, and cannot be used for semiconductor wafers of other diameters. For example, it is generally not possible to upgrade equipment configured for 200 mm diameter wafers to process 300 mm diameter wafers. Downgrading equipment configured for 300 mm diameter wafers typically requires modifying the equipment, for example, by replacing the wafer transport system, weighing tray, and other components.

[0046] The support may comprise or be a pan, such as a balance pan or a weighing pan.

[0047] Supporting the wafer during weight measurement means that the weight of the wafer is borne by a support.

[0048] The support may alternatively be referred to as a measurement area, on which the wafer is loaded to perform weight measurements.

[0049] The support can be connected or coupled to a force sensor, a force transducer, a gravity sensor, a gravity sensor or a load cell so that the gravity of the wafer loaded on the support is transferred from the support to the force sensor, the force transducer, the gravity sensor, the gravity sensor or the load cell.

[0050] The support includes a plurality of contact elements configured to contact the underside of the wafer at a distance less than or equal to D / 3 from the edge of the wafer.

[0051] The term contact element may mean a contact component or a contact member.

[0052] The term contact element may mean a wafer contact element, or a wafer contact component, or a wafer contact member.

[0053] The contact element may be a support element, a support component, or a support member.

[0054] The distance may be a radial distance.

[0055] The distance may be measured along the plane of the wafer and / or along the bottom or lower surface of the wafer.

[0056] The underside of the wafer may refer to the bottom surface or side of the wafer and / or the surface or side of the wafer facing the weighing device during weight measurement and / or the lower surface or side of the wafer.

[0057] Each of the plurality of contact elements is configured to contact the wafer underside at a distance less than or equal to D / 3 from the wafer edge.

[0058] Each of the plurality of contact elements is configured to contact the wafer underside at a corresponding location on the wafer underside that is a distance less than or equal to D / 3 from the wafer edge.

[0059] Each of the plurality of contact elements may be configured to contact the wafer underside at the same distance from the wafer edge. Alternatively, different contact elements may be configured to contact the wafer underside at different distances from the wafer edge.

[0060] The edge of the wafer may refer to the circumferential edge, or the circumference, or the border, or the outer periphery, or the radially outer edge of the underside of the wafer.

[0061] The weighing device may be configured or adapted to perform weight measurement on a wafer having a specific diameter D.

[0062] The support may be configured or adapted to support the wafer during weight measurement.

[0063] The weighing device can be used to measure the weight of a wafer having a diameter of 300 mm. Therefore, the plurality of contact elements are configured to contact the underside of the wafer at a distance of less than or equal to 100 mm from the edge of the wafer. The plurality of contact elements can be configured to contact the underside of the wafer at a distance of less than or equal to 90 mm, or 80 mm, or 75 mm, or 70 mm, or 60 mm, or 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from the edge of the wafer.

[0064] Alternatively, the weighing device can be used to perform weight measurement on a wafer having a diameter of 200 mm. Therefore, the plurality of contact elements are configured to contact the underside of the wafer at a distance of less than or equal to 67 mm from the edge of the wafer (to two significant figures). The plurality of contact elements can be configured to contact the underside of the wafer at a distance of less than or equal to 60 mm, or 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from the edge of the wafer.

[0065] Alternatively, the weighing device can be used to perform weight measurement on a wafer having a diameter of 450 mm. Thus, the plurality of contact elements are configured to contact the underside of the wafer at a distance of less than or equal to 150 mm from the edge of the wafer. The plurality of contact elements can be configured to contact the underside of the wafer at a distance of less than or equal to 140 mm, or 130 mm, or 120 mm, or 112.5 mm, or 110 mm, or 100 mm, or 90 mm, or 80 mm, or 70 mm, or 60 mm, or 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from the edge of the wafer.

[0066] The plurality of contact elements may extend perpendicularly to a main plane or surface or face of the support.

[0067] There may be three contact elements. Three contact elements may be preferred because the contact points of the three contact elements configured to contact the wafer will always lie in a single plane. This may mean that the wafer is stably supported by the contact elements.

[0068] There may be only three contact elements, or exactly three contact elements.

[0069] Generally speaking, the three contact elements are distributed around the center of the support to form a triangle around the center of the support (when the support is viewed perpendicularly to a major plane, surface or face of the support).

[0070] The three contact elements may be arranged to form an equilateral triangle around the centre of the support (when the support is viewed perpendicularly to a major plane, surface or face of the support).

[0071] The center of the support may refer to the point or position where the weighing axis or weighing direction of the weighing device (for example, the direction in which the load cell of the weighing device measures gravity) passes through the support (when the support is viewed perpendicular to the main plane, main surface or main face of the support).

[0072] The center of the support may refer to a point or position below the center of the wafer when the wafer is loaded onto the weighing device.

[0073] The center of the support may refer to a point or position below the center of mass of the wafer when the wafer is loaded onto the weighing device.

[0074] However, in other embodiments, there may be a different number of contact elements. For example, there may be more than three contact elements.

[0075] There may be three or more contact elements.

[0076] The term contact element may mean a contact member or a contact component.

[0077] The plurality of contact elements may be configured to contact the underside of the wafer at a distance less than or equal to D / 4, or D / 5, or D / 6, or D / 7, or D / 8, or D / 9, or D / 10, or D / 11, or D / 12, or D / 13, or D / 14, or D / 15, or D / 16, or D / 17, or D / 18, or D / 19, or D / 20 from the edge of the wafer.

[0078] Each of the plurality of contact elements may be configured to contact an underside of the wafer at a distance less than or equal to a specified distance from an edge of the wafer.

[0079] Each of the plurality of contact elements may be configured to contact the wafer underside at a corresponding location on the wafer underside that is less than or equal to a specified distance from an edge of the wafer.

[0080] The plurality of contact elements may include or be pins, such as wafer support pins. For example, each contact element may include or be a pin.

[0081] Each of the plurality of contact elements may comprise a rod or a cylinder.

[0082] The weighing device can be used to measure the weight of a wafer having a diameter of 200 mm, or 300 mm, or 450 mm. The specific diameter D can therefore be 200 mm, or 300 mm, or 450 mm.

[0083] The plurality of contact elements may include two or more contact elements of different lengths. For example, each of the plurality of contact elements may have a different corresponding length.

[0084] There may be three contact elements (exactly or only three contact elements), and each of the three contact elements may have a different respective length.

[0085] There may be three or more contact elements, and the three or more contact elements may include contact elements of two or more different lengths.

[0086] The plurality of contact elements may include two or more contact elements of different lengths to support the semiconductor wafer in a more horizontal or more lateral orientation (compared to an example in which the contact elements all have the same length), and / or to support the semiconductor wafer in a substantially or approximately horizontal or lateral orientation, and / or to support the wafer in a horizontal or lateral orientation.

[0087] The main plane or face or surface of a support (eg a balance pan or weighing pan) may not be horizontal or transverse.

[0088] For example, a weighing device may include a load cell, and the load cell and / or the housing surrounding the load cell may not be horizontal. Consequently, a support connected or coupled to the load cell may also not be horizontal.

[0089] Alternatively, the load cell may be level, but the support may not be level, for example due to variations in support manufacturing.

[0090] In this example, providing contact elements of different lengths means that the wafer can be supported in a more horizontal or lateral orientation than if the contact elements were all of the same length.

[0091] The length of the contact element can be configured so that the top of the contact element is roughly or substantially arranged on a transverse plane, or a roughly transverse plane (for example, a plane that is inclined less than 5 degrees relative to the transverse direction), or a plane that is more horizontal and / or closer to the transverse direction than the main plane or main surface or main surface of the support member.

[0092] The plane formed by the top of the contact element (or the best fit plane fitted to the top of the contact element) may be more horizontal / closer to horizontal (or lateral) than the plane formed by the main plane or main surface or main face of the bottom of the contact element or support.

[0093] Therefore, when the wafer is loaded onto the weighing device, the semiconductor wafer is supported in a more horizontal or lateral orientation than if the contact elements all had the same length.

[0094] In general, the length of the contact elements can be configured and / or arranged and / or selected to support the wafer in a more horizontal (or lateral) direction (compared to if the contact elements all had the same length), or in a substantially horizontal (or lateral) direction, or in a horizontal (or lateral) direction.

[0095] The length of a contact element may mean the distance that the contact element extends from a main plane or face or surface of the support in a direction perpendicular to the main plane or face or surface of the support.

[0096] The length of a contact element may refer to the longitudinal length or dimension of the contact element.

[0097] One or more of the plurality of contact elements may have an adjustable length. For example, each of the plurality of contact elements may have an adjustable length. Thus, the length of one or more contact elements may be adjusted to achieve a desired length.

[0098] According to a second aspect of the present invention, there is provided an apparatus comprising the weighing device according to the first aspect of the present invention.

[0099] The apparatus according to the second aspect of the present invention may include any of the features of the above-described weighing device according to the first aspect of the present invention.

[0100] The apparatus according to the second aspect of the present invention may have any one or any combination of the following optional features (where compatible).

[0101] The apparatus may be used to determine information related to the quality of a semiconductor wafer, such as the quality of the semiconductor wafer, a change in the quality of the semiconductor wafer, or a difference between the quality of the semiconductor wafer and the quality of a reference wafer.

[0102] The device may be a semiconductor wafer quality measurement device.

[0103] The equipment can be configured to process semiconductor wafers of a specific diameter, such as 200 mm, 300 mm, or 450 mm.

[0104] The apparatus may include a wafer conveyor configured to move the wafer to a support of the weighing device. The wafer conveyor may be configured to convey wafers having a specific diameter.

[0105] The apparatus may include monitoring means configured to determine a buoyancy force exerted on the wafer by the atmosphere in the measurement chamber.

[0106] Calculation of semiconductor wafer mass may include compensating for the buoyancy force exerted on the wafer by the atmosphere in the measurement chamber.

[0107] The monitoring device may include one or more of the following: a temperature monitor, a pressure monitor, and a humidity monitor (or a temperature sensor, or a pressure sensor, or a humidity sensor).

[0108] An apparatus according to a second aspect of the present invention may include a plurality of wafer support elements for supporting the wafer from below while the wafer is being loaded onto the support.

[0109] The term wafer support element may refer to a wafer support component or a wafer support member.

[0110] The term wafer support element may mean a wafer contact element, a wafer contact component or a wafer contact member.

[0111] The wafer supporting element being used to support the wafer from below when the wafer is being loaded onto the support may mean that the wafer supporting element is used to contact the underside of the wafer to support the wafer when the wafer is being loaded onto the support.

[0112] In other words, the wafer supporting element supporting the wafer from below may mean that the contact point between the wafer supporting element and the wafer is below or under the wafer and / or on the underside or bottom of the wafer.

[0113] The wafer supporting element being used to support the wafer from below when the wafer is being loaded onto the support may mean that the wafer supporting element is used to contact the wafer from below or under the wafer to support the wafer when the wafer is being loaded onto the support.

[0114] Each of the plurality of wafer support elements may be configured to contact an underside of the wafer to support the wafer when the wafer is loaded onto the support.

[0115] For example, there may be three wafer support elements, or three or more wafer support elements.

[0116] The wafer support element may include a wafer holder or a wafer hook.

[0117] The wafer support element may be used to support the wafer while the wafer is being transferred onto the support.

[0118] The wafer support element may be configured to contact the wafer from below to support the wafer before the wafer is loaded onto the support.

[0119] The wafer support element may be configured to no longer contact the wafer once the wafer has been loaded onto the support.

[0120] The wafer support element may be configured to support wafers having a diameter of 200 mm, 300 mm, or 450 mm.

[0121] One of the plurality of contact elements may be configured to contact the underside of the wafer (when the wafer is supported by the support) at a distance less than or equal to 50 mm from a position at which one of the plurality of wafer supporting elements is configured to contact the underside of the wafer (when the wafer is supported by the wafer supporting element).

[0122] The contact element of the plurality of contact elements may be configured to contact a position on the underside of the wafer (when the wafer is supported by the support member), wherein the position is less than or equal to 50 mm away from a position on the underside of the wafer at which one of the plurality of wafer supporting elements is configured to contact the underside of the wafer (when the wafer is supported by the wafer supporting element).

[0123] In particular, if the wafer is not level and / or flat, the edge of the wafer may contact one or more wafer support elements when the wafer is loaded onto the weighing device. In this case, part of the weight of the wafer may be supported by the wafer support elements, making the weight measurement incorrect or inaccurate.

[0124] In this aspect, one of the plurality of contact elements is configured to contact the underside of the wafer (when the wafer is supported by the support) at a distance of less than or equal to 50 mm from a position at which one of the plurality of wafer support elements is configured to contact the underside of the wafer (when the wafer is supported by the wafer support element). Thus, the position of the edge of the wafer near the wafer support element can be better controlled and / or more clearly defined, so that contact between the wafer and the wafer support element when the wafer is supported by the support can be prevented or reduced.

[0125] The 50 mm distance may be measured along the plane of the wafer and / or along the bottom or lower surface of the wafer.

[0126] The contact element may be configured to contact the underside of the wafer at a distance of less than or equal to 40 mm, or 30 mm, or 20 mm, or 10 mm from a position where the wafer support element is configured to contact the underside of the wafer.

[0127] Each of the plurality of contact elements may be configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a location where one of the plurality of wafer support elements is configured to contact the underside of the wafer.

[0128] Each of the plurality of contact elements may be configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a location where a corresponding wafer support element of the plurality of wafer support elements is configured to contact the underside of the wafer.

[0129] Each of the plurality of contact elements may be configured to contact the underside of the wafer at a corresponding position on the underside of the wafer that is less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm away from a position on the underside of the wafer at which one of the plurality of wafer supporting elements (or the corresponding wafer supporting element) is configured to contact the underside of the wafer.

[0130] There may be three (only or exactly three) contact elements and three (only or exactly three) wafer support elements. Each of the three contact elements may be configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from the position where the corresponding wafer support element of the three wafer support elements is configured to contact the underside of the wafer.

[0131] There may be three or more contact elements.

[0132] There may be three or more wafer support elements.

[0133] The number of contact elements may be the same as the number of wafer support elements. Each contact element may be configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a location where a corresponding wafer support element is configured to contact the underside of the wafer.

[0134] The apparatus may include a measurement chamber having a cover; the weighing device may be within the measurement chamber; and the plurality of wafer support elements may be attached to, connected to, integrated into, or provided on the cover.

[0135] The apparatus may include a measurement chamber having a cover; a weighing device may be located within the measurement chamber; and the plurality of wafer support elements may be located on an underside of the cover. The underside of the cover is a surface facing the interior of the measurement chamber when the cover is on the measurement chamber.

[0136] The measuring chamber may accommodate and / or surround the weighing device.

[0137] The cover may be a top surface or a portion of the measurement chamber.

[0138] The plurality of wafer support elements may be attached to an underside of the cover.

[0139] The cover is removable from the measuring chamber.

[0140] The cover can be moved vertically upward relative to the main body of the measurement chamber to move the cover away from the main body of the measurement chamber, and can be moved vertically downward relative to the main body of the measurement chamber to position the cover on the main body of the measurement chamber.

[0141] For example, the apparatus may include one or more actuators connected or coupled to the cover and operable to move the cover relative to the body of the measurement chamber. Movement of the cover may be controlled by a controller of the apparatus.

[0142] The wafer support element may be configured to suspend the wafer below the bottom surface of the lid.

[0143] The wafer can thus be held or supported by the wafer support element below the bottom surface of the cover, with a predetermined distance between the wafer and the bottom surface of the cover.

[0144] The apparatus may be configured (eg the wafer support element and / or the contact element may be configured and / or adapted and / or arranged and / or disposed) such that the wafer is loaded from the wafer support element onto the support when the cover is positioned on the measurement chamber.

[0145] For example, when the cover is positioned on the measurement chamber, the contact point of the contact element may be higher in the vertical direction than the contact point of the wafer support element.

[0146] According to a third aspect of the present invention, a weighing device for measuring the weight of a wafer is provided, the weighing device comprising a support member for supporting the wafer during weight measurement, wherein: The support includes a plurality of contact elements located at least 50 mm from the center of the support and configured to contact the underside of the wafer to support the wafer during weight measurement.

[0147] Thus, the plurality of contact elements can support a 300 mm semiconductor wafer closer to the wafer edge than in the previous example.

[0148] The weighing device according to the third aspect of the present invention may have any features of the weighing device according to the first aspect of the present invention, unless they are incompatible with the features of the third aspect described herein.

[0149] The weighing device according to the third aspect of the present invention may have any one or any combination of the following optional features (where compatible).

[0150] At least 50 mm from the center of the support means greater than or equal to, more than or equal to 50 mm from the center of the support.

[0151] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0152] The center of the support may mean the center of the support when the support is viewed perpendicularly to a main plane or main face or main surface of the support.

[0153] The center of the support may refer to the point where the weighing axis of the weighing device or the weighing direction (eg the direction in which the load cell of the weighing device measures gravity) passes through the support.

[0154] The center of the support may refer to a point or location on the support that is below the center of the wafer when the wafer is loaded onto the support.

[0155] The center of the support may refer to a point or position below the center of mass of the wafer when the wafer is loaded onto the weighing device.

[0156] The center of the support may be a point on the support that is above the central axis of the support.

[0157] The plurality of contact elements may be located at least 60 mm, or at least 70 mm, or at least 75 mm, or at least 80 mm, or at least 90 mm, or at least 100 mm, or at least 110 mm, or at least 120 mm, or at least 130 mm, or at least 140 mm from the center of the support.

[0158] The plurality of contact elements may each be located at the same distance from the center of the support. Alternatively, each contact element may be located at a different respective distance from the center of the support.

[0159] The distance from the center of the support may be measured when viewing the support perpendicularly to a major plane or face or surface of the support.

[0160] The distance from the center of the support may be a radial distance from the center of the support, for example on a major plane or face or surface of the support.

[0161] The distance from the center of the support may be measured along a major plane or face or surface of the support.

[0162] There may be three or more contact elements.

[0163] The weighing device can be used to measure the weight of a wafer having a diameter of 300 mm.

[0164] The weighing device may be configured or adapted to perform weight measurement on a wafer having a diameter of 300 mm.

[0165] The weighing device according to the third aspect may be included in the apparatus according to the second aspect, which apparatus may include any of the features of the second aspect discussed above unless incompatible with the features of the third aspect described herein.

[0166] According to a fourth aspect of the present invention, a weighing device for performing weight measurement on a wafer having a diameter of 200 mm is provided, the weighing device comprising a support for supporting the wafer during weight measurement, wherein: the support comprises a plurality of contact elements located at least 33 mm from a center of the support and configured to contact the underside of the wafer to support the wafer during weight measurement.

[0167] The weighing device according to the fourth aspect of the present invention may have any features of the weighing device according to the first aspect or the third aspect of the present invention, unless they are incompatible with the features of the fourth aspect described herein.

[0168] The weighing device according to the fourth aspect of the present invention may have any one or any combination of the following optional features (where compatible).

[0169] The plurality of contact elements may be located at a distance of at least 40 mm, or at least 50 mm, or at least 60 mm, or at least 70 mm, or at least 80 mm, or at least 90 mm from the center of the support.

[0170] There may be three or more contact elements.

[0171] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0172] The weighing device according to the fourth aspect may be included in the apparatus according to the second aspect, which apparatus may include any of the features of the second aspect discussed above unless incompatible with the features of the fourth aspect described herein.

[0173] According to a fifth aspect of the present invention, a weighing device for performing weight measurement on a wafer having a diameter of 450 mm is provided, the weighing device comprising a support for supporting the wafer during weight measurement, wherein: the support comprises a plurality of contact elements located at least 75 mm from the center of the support and configured to contact the underside of the wafer to support the wafer during weight measurement.

[0174] The weighing device according to the fifth aspect of the present invention may have any features of the weighing device according to the first aspect, the third aspect or the fourth aspect of the present invention, unless they are incompatible with the features of the fifth aspect described herein.

[0175] The weighing device according to the fifth aspect of the present invention may have any one or any combination of the following optional features (where compatible).

[0176] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0177] There may be three or more contact elements.

[0178] The plurality of contact elements may be located at a distance of at least 85 mm, or at least 95 mm, or at least 105 mm, or at least 112.5 mm, or at least 115 mm, or at least 125 mm, or at least 135 mm, or at least 145 mm, or at least 155 mm, or at least 165 mm, or at least 175 mm, or at least 185 mm, or at least 195 mm, or at least 205 mm, or at least 215 mm from the center of the support.

[0179] The weighing device according to the fifth aspect may be included in the apparatus according to the second aspect, which may include any of the features of the second aspect discussed above, unless incompatible with the features discussed above, unless incompatible with the features of the fifth aspect described herein.

[0180] According to a sixth aspect of the present invention, there is provided an apparatus comprising: A weighing device for performing weight measurement on a wafer, the weighing device comprising a support for supporting the wafer during weight measurement, wherein the support comprises a plurality of contact elements configured to contact an underside of the wafer to support the wafer during weight measurement; and a plurality of wafer support elements for supporting the wafer from below while the wafer is being loaded onto the support; One of the plurality of contact elements is configured to contact the underside of the wafer (when the wafer is supported by the support) at a distance less than or equal to 50 mm from a position at which one of the plurality of wafer supporting elements is configured to contact the underside of the wafer (when the wafer is supported by the wafer supporting element).

[0181] The apparatus according to the sixth aspect of the present invention may include any features of the first to fifth aspects described above, unless they are incompatible with the features of the sixth aspect described herein.

[0182] The apparatus according to the sixth aspect of the present invention may include any one or any combination of the following optional features (where compatible).

[0183] The wafer supporting element being used to support the wafer from below when the wafer is being loaded onto the support may mean that the wafer supporting element is used to contact the underside of the wafer to support the wafer when the wafer is being loaded onto the support.

[0184] In other words, the wafer supporting element supporting the wafer from below may mean that the contact point between the wafer supporting element and the wafer is below or under the wafer and / or on the underside or bottom of the wafer.

[0185] The wafer supporting element being used to support the wafer from below when the wafer is being loaded onto the support may mean that the wafer supporting element is used to contact the wafer from below or under the wafer to support the wafer when the wafer is being loaded onto the support.

[0186] Each of the plurality of wafer support elements may be configured to contact an underside of a wafer to support the wafer when the wafer is being loaded onto the support.

[0187] The contact element is configured to contact the underside of the wafer (when the wafer is supported by the support) at a position on the underside of the wafer that is less than or equal to 50 mm from a position on the underside of the wafer at which one of the plurality of wafer supporting elements is configured to contact the underside of the wafer (when the wafer is supported by the wafer supporting element).

[0188] The wafer support element may be configured to no longer contact the wafer once the wafer has been loaded onto the support.

[0189] The contact element may be configured to contact the underside of the wafer at a distance of less than or equal to 40 mm, or 30 mm, or 20 mm, or 10 mm from a position where the wafer support element is configured to contact the underside of the wafer.

[0190] Each of the plurality of contact elements may be configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a location where one of the plurality of wafer support elements is configured to contact the underside of the wafer.

[0191] Each of the plurality of contact elements may be configured to contact the underside of the wafer at a distance less than or equal to a specified distance from a location at which a corresponding one of the plurality of wafer support elements is configured to contact the underside of the wafer.

[0192] Each of the plurality of contact elements may be configured to contact the wafer underside at a corresponding location on the wafer underside that is less than or equal to a specified distance from a location at which a corresponding one of the plurality of wafer support elements is configured to contact the wafer underside.

[0193] There may be three (only or exactly three) contact elements.

[0194] There may be three (only or exactly three) wafer support elements.

[0195] Each of the three contact elements may be configured to contact the underside of the wafer at a distance less than or equal to a specified distance from a location where a corresponding one of the three wafer support elements is configured to contact the underside of the wafer.

[0196] There may be three or more contact elements.

[0197] There may be three or more wafer support elements.

[0198] The number of contact elements may be the same as the number of wafer support elements. Each contact element may be configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a location where a corresponding wafer support element is configured to contact the underside of the wafer.

[0199] The plurality of contact elements may be pins. For example, each contact element may include or be a pin.

[0200] The plurality of contact elements may include two or more contact elements of different lengths.

[0201] The plurality of contact elements may include two or more contact elements of different lengths to support the wafer in a more horizontal orientation during weight measurement.

[0202] For example, there may be three contact elements, and each of the three contact elements may have a different respective length.

[0203] There may be three or more contact elements, and the three or more contact elements may include contact elements of two or more different lengths.

[0204] One or more of the plurality of contact elements may have an adjustable length.

[0205] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0206] The weighing device can be used to measure the weight of a wafer having a specific diameter D; and one or more of the plurality of contact elements can be configured to contact the underside of the wafer at a distance less than or equal to D / 3, or D / 4, or D / 5, or D / 6, or D / 7, or D / 8, or D / 9, or D / 10, or D / 11, or D / 12, or D / 13, or D / 14, or D / 15, or D / 16, or D / 17, or D / 18, or D / 19, or D / 20 from the edge of the wafer.

[0207] The weighing device can be used to measure the weight of wafers having a diameter of 200 mm, 300 mm or 450 mm.

[0208] The weighing device may be configured and / or adapted to perform weight measurement on a wafer having a specific diameter D.

[0209] One or more of the plurality of contact elements may be configured to contact the wafer underside at a distance less than or equal to 100 mm, or 90 mm, or 80 mm, or 75 mm, or 70 mm, or 60 mm, or 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from the wafer edge.

[0210] One or more of the plurality of contact elements may be located at least 50 mm, or at least 60 mm, or at least 70 mm, or at least 75 mm, or at least 80 mm, or at least 90 mm, or at least 100 mm, or at least 110 mm, or at least 120 mm, or at least 130 mm, or at least 140 mm from the center of the support.

[0211] The apparatus may include a measurement chamber having a cover; the weighing device may be within the measurement chamber; and the plurality of wafer support elements may be attached to the cover (and / or provided on an underside of the cover).

[0212] The apparatus may be configured such that when the cover is positioned on the measurement chamber, the wafer is loaded from the wafer support element onto the support.

[0213] According to a seventh aspect of the present invention, there is provided a weighing device for measuring the weight of a wafer, the weighing device comprising a support member for supporting the wafer during weight measurement, wherein: The support includes a plurality of contact elements configured to contact an underside of the wafer to support the wafer during weight measurement; and The plurality of contact elements includes two or more contact elements of different lengths.

[0214] The weighing device according to the seventh aspect of the present invention may include any features of the weighing device according to the first, third, fourth or fifth aspects of the present invention described above, unless they are incompatible with the features of the seventh aspect described herein.

[0215] The weighing device according to the seventh aspect of the present invention may include any one or any combination of the following optional features (where compatible).

[0216] The plurality of contact elements may include two or more contact elements of different lengths to support the semiconductor wafer in a more horizontal orientation during weight measurement.

[0217] There may be three or more contact elements.

[0218] There may be exactly or only three contact elements.

[0219] The three contact elements may have different respective lengths.

[0220] There may be three or more contact elements, and the three or more contact elements may include contact elements of two or more different lengths.

[0221] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0222] At least one of the plurality of contact elements may have an adjustable length.

[0223] The weighing device according to the seventh aspect of the present invention may be included in the device according to the second or sixth aspect of the present invention described above, and the device may include any features of the second or sixth aspect discussed above unless they are incompatible with the features of the seventh aspect described herein.

[0224] According to an eighth aspect of the present invention, a weighing device for measuring the weight of a wafer is provided, the weighing device comprising a support member for supporting the wafer during weight measurement, wherein: The support includes a plurality of contact elements configured to contact the underside of the wafer to support the wafer during weight measurement; and At least one of the plurality of contact elements has an adjustable length.

[0225] The weighing device according to the eighth aspect of the present invention may include any features of the weighing device according to the first, third, fourth, fifth or seventh aspects of the present invention described above, unless they are incompatible with the features of the eighth aspect described herein.

[0226] There may be three or more contact elements.

[0227] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0228] The weighing device according to the eighth aspect of the present invention may be included in the device according to the second or sixth aspect of the present invention described above, and the device may include any features of the second or sixth aspect discussed above unless they are incompatible with the features of the eighth aspect described herein.

[0229] According to a ninth aspect of the present invention, a method is provided, comprising: performing a weight measurement on a semiconductor wafer having a specific diameter D; wherein the method includes supporting the wafer from below at a distance less than or equal to D / 3 from an edge of the wafer during the weight measurement.

[0230] The method according to the ninth aspect may include any of the features of the first to eighth aspects discussed above, unless incompatible with the features of the ninth aspect described herein.

[0231] Supporting the wafer from below may mean that the point of contact with the wafer is on the underside or bottom of the wafer.

[0232] Supporting the wafer from below at a distance less than or equal to D / 3 from the edge of the wafer during weight measurement may include or mean contacting the wafer at a location on the underside of the wafer at a distance less than or equal to D / 3 from the edge of the wafer during weight measurement.

[0233] Supporting the wafer from below at a distance less than or equal to D / 3 from the edge of the wafer during weight measurement may include or mean contacting the wafer at a plurality of locations on the underside of the wafer during weight measurement, each location being at a distance less than or equal to D / 3 from the edge of the wafer.

[0234] The method may include supporting the wafer from below at a distance less than or equal to D / 4, or D / 5, or D / 6, or D / 7, or D / 8, or D / 9, or D / 10, or D / 11, or D / 12, or D / 13, or D / 14, or D / 15, or D / 16, or D / 17, or D / 18, or D / 19, or D / 20 from the edge of the wafer.

[0235] Supporting the wafer from below at a distance less than or equal to a specified distance from an edge of the wafer includes contacting the underside of the wafer at a location on the underside of the wafer that is less than or equal to the specified distance from the edge of the wafer.

[0236] The method may include supporting the wafer from below using a plurality of contact elements configured to contact an underside of the wafer at a distance less than or equal to a specified distance from an edge of the wafer.

[0237] There may be three (only or exactly three) contact elements. There may be three or more contact elements.

[0238] The wafer may be a semiconductor wafer, such as a silicon wafer.

[0239] According to a tenth aspect of the present invention, a method is provided, comprising: A weighing device is provided for performing weight measurement on a wafer, the weighing device comprising a support member for supporting the wafer during weight measurement, the support member comprising a plurality of contact elements configured to contact an underside of the wafer to support the wafer during weight measurement; The method includes setting the length of the plurality of contact elements to support the wafer in a more horizontal orientation during weight measurement.

[0240] The method according to the tenth aspect may include any of the features of the first to ninth aspects discussed above, unless incompatible with the features of the tenth aspect described herein.

[0241] According to an eleventh aspect of the present invention, there is provided an apparatus comprising: a measurement chamber, wherein the measurement chamber has a removable cover; and a plurality of wafer support elements for supporting a wafer from below, wherein the plurality of wafer support elements are provided on the cover.

[0242] An apparatus according to an eleventh aspect of the present invention may include any of the features of the first to tenth aspects discussed above, unless incompatible with the features of the eleventh aspect described herein.

[0243] For example, the lid and / or wafer support component of this aspect may have any of the features of the lid and / or wafer support component of any other aspect discussed above, unless incompatible.

[0244] The apparatus according to the eleventh aspect of the present invention may include any one or any combination of the following optional features (where compatible).

[0245] The wafer supporting element being used to support the wafer from below may mean that the wafer supporting element is used to contact the lower side of the wafer to support the wafer.

[0246] In other words, the wafer supporting element supporting the wafer from below may mean that the contact point between the wafer supporting element and the wafer is below or under the wafer and / or on the underside or bottom of the wafer.

[0247] The wafer supporting element being used to support the wafer from below may mean that the wafer supporting element is used to contact the wafer from below or under the wafer to support the wafer.

[0248] Each of the plurality of wafer support elements may be configured to contact an underside of the wafer to support the wafer.

[0249] Providing the wafer support element on the cover may mean that the wafer support element is disposed on the cover, attached to the cover, fixed to the cover, or integral with the cover.

[0250] The wafer support element may be provided on the underside or bottom surface or side of the cover.

[0251] The lower side of the cover means the side of the cover facing the interior of the measurement chamber when the cover is positioned on the measurement chamber.

[0252] The wafer supporting element may be a wafer hook.

[0253] There may be three (only or exactly three) wafer support elements. There may be three or more wafer support elements.

[0254] The three wafer support elements may be configured to be evenly spaced around the circumference of the wafer when the wafer is supported by the three wafer support elements.

[0255] For example, three wafer support elements may be arranged to form an equilateral triangle between the three wafer support elements.

[0256] The contact points of the three wafer support elements may be arranged to be evenly spaced around the circumference of the wafer when the wafer is supported by the three wafer support elements.

[0257] For example, the contact points of the three wafer support elements may be arranged to form an equilateral triangle between the contact points of the three wafer support elements.

[0258] The apparatus may include a weighing device for measuring the weight of the wafer, wherein the weighing device is located in the measuring chamber.

[0259] The measuring chamber may accommodate and / or surround the weighing device.

[0260] The cover may be a top surface or a portion of the measurement chamber.

[0261] The cover can be moved vertically upward relative to the main body of the measurement chamber to move the cover away from the main body of the measurement chamber, and can be moved vertically downward relative to the main body of the measurement chamber to position the cover on the main body of the measurement chamber.

[0262] For example, the apparatus may include one or more actuators connected or coupled to the cover and operable to move the cover relative to the body of the measurement chamber. Movement of the cover may be controlled by a controller of the apparatus.

[0263] The wafer support element may be configured to suspend the wafer below the underside (bottom surface) of the lid.

[0264] The wafer can thus be held or supported by the wafer support element below the underside (bottom surface) of the cover, with a predetermined spacing between the wafer and the underside of the cover.

[0265] The apparatus may be configured (eg the wafer support element and / or the weighing device may be configured and / or adapted and / or arranged and / or disposed) such that the wafer is loaded from the wafer support element onto the weighing device when the cover is positioned on the measurement chamber.

[0266] The weighing apparatus may include a support for supporting the wafer during weight measurement. The apparatus may be configured (e.g., the wafer support element and / or the support may be configured and / or adapted and / or arranged and / or positioned) such that when the cover is positioned on the measurement chamber, the wafer is loaded from the wafer support element onto the support.

[0267] The support may include a plurality (eg, three or more) of contact elements configured to contact the underside of the wafer to support the wafer during weight measurement.

[0268] When the cover is positioned on the measurement chamber, the contact point of the contact element may be higher in the vertical direction than the contact point of the wafer supporting element.

[0269] The apparatus may include a seal located between the cover and the measurement chamber when the cover is positioned on the measurement chamber. For example, the seal may be provided on the cover and / or on the body of the measurement chamber.

[0270] Each of the plurality of wafer supports is substantially L-shaped.

[0271] Each of the plurality of wafer support elements may be configured to extend inwardly relative to a wafer supported by the plurality of wafer support elements.

[0272] Each of the plurality of wafer support elements may be configured to extend radially inward relative to a wafer supported by the plurality of wafer support elements.

[0273] For example, each wafer support element may include a first portion extending substantially vertically downward from the underside of the cover, and a second portion extending substantially laterally from the first portion. The second portion may be arranged to extend substantially radially inward relative to the wafer supported by the wafer support element.

[0274] The second portion of the wafer support element may be long enough to allow a wafer to be inserted from the side (ie, laterally) between any two wafer support elements and then lowered onto the second portion of the wafer support element.

[0275] For example, the wafer may be supported from below by an end effector or other wafer support, and the end effector may be used to position the wafer between the wafer support elements and lower the wafer onto the second portion of the wafer support elements.

[0276] Each wafer support element may include a protrusion, such as a bump or pin, for contacting the underside of the wafer when supported by the wafer support element. This minimizes contact between the wafer and the wafer support element and, therefore, contamination of the wafer. For example, the protrusion may be located on the upper side of the second portion of the wafer support element.

[0277] Where compatible, the features of one or more of any of the above aspects of the present invention may be combined in any order. Simple diagram description

[0278] Embodiments of the present invention will now be discussed by way of example only with reference to the accompanying drawings, in which:

[0279] Figure 1 shows a device according to a comparative example;

[0280] Figure 2 shows a device according to a comparative example;

[0281] Figure 3 shows a device according to a first embodiment of the present invention;

[0282] Figure 4 shows a device according to a first embodiment of the present invention;

[0283] Figure 5 (a) and 5 (b) show a balance pan that can be used in the first embodiment of the present invention;

[0284] Figure 6 shows a device according to a second embodiment of the present invention;

[0285] Figure 7 shows a device according to a second embodiment of the present invention;

[0286] Figure 8 (a) and 8 (b) show a balance pan that can be used in a second embodiment of the present invention;

[0287] Figure 9 shows a device according to a third embodiment of the present invention;

[0288] Figures 10(a) and 10(b) show a balance pan that can be used in a third embodiment of the present invention; and

[0289] 11( a ) and 11 ( b ) illustrate a cover member that can be used for a measurement chamber in an embodiment of the present invention. Implementation Method

[0290] Aspects and embodiments of the present invention will now be discussed with reference to the accompanying drawings. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned herein are incorporated herein by reference.

[0291] FIG1 and FIG2 illustrate an apparatus 1 according to a comparative example. Apparatus 1 may be a semiconductor wafer quality measurement apparatus for determining information related to semiconductor wafer quality, such as the mass of the semiconductor wafer, a change in the mass of the semiconductor wafer, or the difference between the mass of the semiconductor wafer and the mass of a reference mass or a counterweight.

[0292] The apparatus 1 includes a measuring chamber 3 . A weighing device 5 for weighing a semiconductor wafer 7 is installed in the measuring chamber 3 . The measuring chamber 3 accommodates and / or surrounds the weighing device 5 .

[0293] The apparatus 1 may be configured to determine the mass of the semiconductor wafer 7 , a mass change of the semiconductor wafer 7 , or a difference between the mass of the semiconductor wafer 7 and the mass of a reference mass or a counterweight based at least on a weight measurement performed on the semiconductor wafer 7 by the weighing device 5 .

[0294] The weighing device 5 is configured to generate a measurement output indicative of a measured weight, such as the weight of a semiconductor wafer 7 loaded on the weighing device 5. The weighing device 5 can measure the weight of the semiconductor wafer 7, or a change in the weight of the semiconductor wafer 7, or a difference between the weight of the semiconductor wafer 7 and the weight of a reference mass or counterweight.

[0295] The measurement output of the weighing device 5 can be an electric signal or an electrical output corresponding to the measured weight. For example, the magnitude of the current or voltage of the electric signal or the electrical output can correspond to the measured weight.

[0296] The measurement chamber 3 can provide a controlled environment around the weighing device 5. For example, the measurement chamber 3 can minimize airflow around the weighing device 5. Additionally or alternatively, the measurement chamber 3 can maintain a substantially uniform temperature around the weighing device 5. For example, the measurement chamber 3 can include a heater or a cooler to maintain a substantially uniform temperature within the measurement chamber 3, e.g., within + / - 0.1°C.

[0297] The weighing device 5 includes a load cell 9 (gravity sensor or gravity transducer). The load cell 9 is configured to convert a force applied to the load cell 9 into an electrical signal or output corresponding to the force (i.e., the magnitude of the current or voltage of the electrical signal or output corresponds to the magnitude of the force).

[0298] The weighing device 5 further includes a balance pan (or weighing pan) 11 for supporting the semiconductor wafer 7 during weight measurement. In particular, the balance pan 11 supports the weight of the semiconductor wafer 7 during weight measurement.

[0299] The balance pan 11 is coupled or connected to the load cell 9 so that the gravity applied to the balance pan 11 is applied to the load cell 9 and measured by the load cell 9. For example, the balance pan 11 may include a shaft coupled or connected to the load cell 9.

[0300] The balance plate 11 includes a plurality of wafer support pins 13 (contact elements). The wafer support pins 13 extend perpendicularly to the principal plane, surface, or face of the balance plate 11. Specifically, when the semiconductor wafer 7 is loaded onto the balance plate 11, the wafer support pins 13 extend perpendicularly to the principal plane, surface, or face of the semiconductor wafer 7 facing the balance plate 11.

[0301] In this comparative example, the balance plate 11 includes three wafer support pins 13 (exactly or only three wafer support pins 13), but a different number of wafer support pins 13 may be provided. For example, in other embodiments, there may be three or more wafer support pins 13.

[0302] The wafer support pins 13 are configured to contact the lower side of the semiconductor wafer 7 loaded on the balance pan 11 to support the semiconductor wafer 7 during weight measurement.

[0303] The wafer support pins 13 may be arranged to form a triangle, such as an equilateral triangle, around the center of the balance pan 11 (when the balance pan 11 is viewed perpendicularly to its main plane or surface or face).

[0304] In this comparative example, each wafer support pin 13 is located 40 mm or less from the center of the balance pan (when the balance pan 11 is viewed perpendicularly to its principal plane or surface or face).

[0305] When a semiconductor wafer 7 having a diameter of 300 mm is loaded on the balance plate 11, each wafer support pin 13 is thus configured to contact the underside of the semiconductor wafer 7 at a distance of more than 110 mm from an edge (eg, outer circumferential edge or peripheral edge) of the semiconductor wafer 7.

[0306] As shown in Figures 1 and 2, the measurement chamber 3 has a removable cover 15 (top surface). Specifically, the cover 15 can be moved vertically upward relative to the main body 19 of the measurement chamber 3 to remove the cover 15 from the main body 19 of the measurement chamber 3, and can be moved vertically downward relative to the main body 19 of the measurement chamber 3 to position the cover 15 on the main body 19 of the measurement chamber 3.

[0307] For example, the apparatus 1 may include one or more actuators connected or coupled to the cover 15 and operable to move the cover 15 relative to the body 19 of the measurement chamber 3. The movement of the cover 15 may be controlled by a controller of the apparatus 1.

[0308] A plurality of wafer hooks 17 are attached to the bottom surface of the cover 15. The plurality of wafer hooks 17 are configured to contact the semiconductor wafer 7 from below to support the semiconductor wafer 7 when the semiconductor wafer 7 is being loaded onto the balance pan 11.

[0309] In this comparative example, there are three wafer hooks 17 , but a different number of wafer hooks 17 may be provided.

[0310] In particular, the wafer hook 17 is configured to suspend the semiconductor wafer 7 below the bottom surface of the cover 15 .

[0311] The number of wafer hooks 17 can be the same as the number of wafer support pins 13. Preferably, there are three wafer hooks 17 and three wafer support pins 13. There can be three or more wafer support pins 13 and three or more wafer hooks 17.

[0312] The semiconductor wafer 7 is thus held or supported by the wafer hooks 17 below the bottom surface of the cover 15 , with a predetermined distance between the semiconductor wafer 7 and the bottom surface of the cover 15 .

[0313] FIG2 shows that the cover 15 is moved away from the main body 19 of the measurement chamber 3 , and the semiconductor wafer 7 is supported below the cover 15 by the wafer hooks 17 .

[0314] FIG. 1 shows the cover 15 positioned on the body 19 of the measuring chamber 3 .

[0315] As shown in FIG1 , the apparatus 1 is configured (e.g., the wafer hook 17 and / or the wafer support pin 13 are configured and / or arranged and / or disposed) such that when the cover 15 is positioned on the main body 19 of the measurement chamber 3 , the semiconductor wafer 7 is loaded onto the weighing device 5 and supported by the balance pan 11 .

[0316] Specifically, when the cover 15 is positioned on the main body 19 of the measurement chamber 3, the tops of the wafer support pins 13 of the balance pan 11 are vertically positioned higher within the measurement chamber 3 than portions of the wafer hooks 17 configured to contact the underside of the semiconductor wafer 7. Therefore, when the cover 15 is positioned on the main body 19 of the measurement chamber 3, the semiconductor wafer 7 is supported on the tops of the wafer support pins 13, rather than on the portions of the wafer hooks 17 configured to contact the underside of the semiconductor wafer 7.

[0317] As described above, during the manufacturing process of a load cell (e.g., load cell 9), the configuration, position, and / or orientation of load cell 9 (and / or the housing surrounding load cell 9) is determined to achieve optimal performance of load cell 9. In this optimal configuration, load cell 9 (and / or the housing surrounding load cell 9) is often not horizontal. In other words, the weighing axis or weighing direction (the direction in which load cell 9 measures gravity) of load cell 9 may not be vertical, and / or the top and / or bottom surfaces of load cell 9 (and / or the housing surrounding load cell 9) may not be horizontal.

[0318] This optimal placement can be achieved by having the load cell 9 (and / or the housing surrounding the load cell 9) include a plurality of legs 21 (or supports) to support the load cell 9 above the bottom surface of the measurement chamber 3. The plurality of legs 21 have different lengths, so that the load cell 9 is not horizontal. For example, the length of one or more legs 21 may be adjustable, so that the legs 21 can be adjusted to optimize the performance of the load cell 9.

[0319] Therefore, as shown in Figures 1 and 2, in this comparative example, the load cell 9 is not horizontal (for illustrative purposes, the inclination of the load cell 9 is exaggerated in Figures 1 and 2).

[0320] As shown in Figures 1 and 2, since the load cell 9 is not horizontal, the balance pan 11 coupled or connected to the load cell 9 is also not horizontal. In other words, when the semiconductor wafer 7 is loaded on the balance pan 11, the main plane or main surface or main face of the balance pan 11 facing the semiconductor wafer 7 is not horizontal or horizontal.

[0321] For example, because the load cell 9 is not horizontal, the axis of the balance pan 11 connected to the load cell 9 may not be vertical, and therefore the main plane or main surface or main face of the balance pan 11 may not be horizontal or horizontal.

[0322] Therefore, when the semiconductor wafer 7 is loaded onto the balance pan 11, the semiconductor wafer 7 is not horizontal or transverse, as shown in Figure 1. In other words, the main plane or main surface or main face of the semiconductor wafer 7 is not horizontal or transverse.

[0323] As shown in FIG. 1 , if the balance pan 11 and therefore the semiconductor wafer 7 are not level, there may be a significant deviation between the expected position of the edge of the semiconductor wafer 7 when the semiconductor wafer 7 is level or sideways and the actual position of the edge of the semiconductor wafer 7 .

[0324] This deviation can cause a number of problems, as discussed above. For example, in some cases, when the semiconductor wafer 7 is loaded onto the balance pan 11, the deviation may be sufficient to cause the edge of the semiconductor wafer 7 to contact one or more wafer hooks 17. This means that part of the weight of the semiconductor wafer 7 will be supported by one or more wafer hooks 17, and the weight measurement will therefore be incorrect.

[0325] Additionally or alternatively, the deviation may mean that the semiconductor wafer 7 is in contact with a portion of the measurement chamber 3, such as the cover 15 or the body 19, or with another portion of the apparatus 1. This means that part of the weight of the semiconductor wafer 7 will be supported by a portion of the measurement chamber 3 or another portion of the apparatus 1, and the weight measurement will therefore be incorrect.

[0326] Apparatus 1 may include a monitoring device configured to measure the buoyancy force exerted on the wafer by the atmosphere in measurement chamber 3. For example, the apparatus may include sensors to monitor the temperature, pressure, and relative humidity within measurement chamber 3. The controller 22 or processor of apparatus 1 may be configured to receive measurements from these sensors and use them to calculate the air density, which may be used to compensate for the buoyancy force in the weight measurements performed by weighing device 5.

[0327] The apparatus 1 may thus be configured to calculate the mass of the semiconductor wafer 7 based on the measurement output of the weighing device 5 and the buoyancy force exerted on the semiconductor wafer 7 by the atmosphere in the measurement chamber 3 .

[0328] The apparatus 1 and / or the weighing device 5 may be configured or adapted to process semiconductor wafers having a specific diameter, such as 200 mm, 300 mm or 450 mm.

[0329] In this embodiment, the apparatus 1 and / or the weighing device are configured to process semiconductor wafers having a diameter of 300 mm.

[0330] For example, the wafer hook 17 and / or the balance plate 11 may be configured or adapted to handle semiconductor wafers having a specific diameter.

[0331] Figures 3 and 4 illustrate an apparatus 23 according to a first embodiment of the present invention. Apparatus 23 is a modified version of apparatus 1 shown in Figures 1 and 2 and the aforementioned comparative example. Apparatus 23 may therefore include any features shown in Figures 1 and 2 and / or the aforementioned comparative example, unless such features are incompatible with and / or replaced by the modifications described below.

[0332] Specifically, as described below, apparatus 23 differs from apparatus 1 of the comparative example in that apparatus 23 includes a balance pan 27, which is different from balance pan 11 of apparatus 1. Any other features (one, more than one, or all) of apparatus 23 may be the same as those of apparatus 1 of the comparative example. For the sake of brevity, these features will not be repeated here. Corresponding features are denoted by the same reference numerals in Figures 3 and 4.

[0333] Specifically, in apparatus 23, the weighing device 5 of apparatus 1 of the comparative example is replaced with a weighing device 25 having a balance pan 27 different from the balance pan 11 of weighing device 5. Any other features (one, more than one, or all) of weighing device 25 may be the same as those of weighing device 5 of apparatus 1. For example, weighing device 25 includes the same load cell 9 as weighing device 5 and may include the same plurality of legs 21 as weighing device 5.

[0334] The balance plate 27 includes a plurality of wafer support pins 29. The wafer support pins 29 extend perpendicularly to the main plane, main surface, or main face of the balance plate 27. Specifically, when the semiconductor wafer 7 is loaded on the balance plate 27, the wafer support pins 29 extend perpendicularly to the main plane, main surface, or main face of the semiconductor wafer 7 from the side of the balance plate 27.

[0335] In this embodiment, the balance plate 27 includes three wafer support pins 29 (exactly or only three wafer support pins 29). Of course, in other embodiments, there may be a different number of wafer support pins 29. For example, in other embodiments, there may be three or more wafer support pins 29.

[0336] The wafer support pins 29 are configured to contact the lower side of the semiconductor wafer 7 loaded on the balance pan 27 to support the semiconductor wafer 7 during weight measurement.

[0337] As in the comparative example, in this embodiment, the load cell 9 is not horizontal. In other words, the weighing axis of the load cell 9 may not be vertical, and / or the top and / or bottom surfaces of the load cell 9 (and / or the housing surrounding the load cell 9) may not be horizontal.

[0338] For example, because the load cell 9 is not horizontal, the axis of the balance pan 27 connected to the load cell 9 may not be vertical, and thus the main plane or main surface or main face of the balance pan 27 may not be horizontal or horizontal.

[0339] Since the load cell 9 is not horizontal, the balance pan 27 coupled or connected to the load cell 9 is also not horizontal. In other words, when the semiconductor wafer 7 is loaded on the balance pan 27, the main plane or main surface or main face of the balance pan 27 facing the semiconductor wafer 7 is not horizontal or horizontal.

[0340] However, in this embodiment, the wafer support pins 29 include at least two wafer support pins 29 of different lengths. In other words, the distances that the wafer support pins 29 extend perpendicularly from the main plane, main surface, or main face of the balance plate 27 include at least two different distances. For example, each wafer support pin 29 may have a different length and extend perpendicularly from the main plane, main surface, or main face of the balance plate 27 by a different distance.

[0341] There may be three wafer support pins 29, and each of the three wafer support pins 29 may have a different respective length.

[0342] Each wafer support pin 29 may have a fixed length. Alternatively, one or more wafer support pins 29 may have an adjustable length.

[0343] The length of the wafer support pin 29 can be configured so that the top of the wafer support pin 29 is roughly or substantially arranged on the transverse plane, or on a roughly transverse plane (for example, a plane inclined less than 5 degrees relative to the transverse plane), or on a plane that is flatter and / or closer to the transverse plane than the main plane or main surface or main surface of the balance pan 27.

[0344] The plane formed by the top of the wafer support pin 29 (or the best fit plane fitted to the top of the wafer support pin 29) may be more horizontal / closer to horizontal (or horizontal) than the plane formed by the bottom of the wafer support pin 29 or the main plane or main surface or main surface of the balance plate 27.

[0345] Compared to an example in which all wafer support pins 29 have the same length, wafer support pins 29 of different lengths can support the wafer 7 in a more horizontal and / or more lateral direction.

[0346] Therefore, when the semiconductor wafer 7 is loaded on the weighing device 25, the semiconductor wafer is closer to horizontal or closer to lateral orientation than in the comparative example.

[0347] Generally speaking, the length of the wafer support pins 29 can be configured and / or arranged and / or selected to support the semiconductor wafer 7 in a more horizontal (or lateral), or substantially horizontal (or lateral), or horizontal (or lateral) orientation (compared to an example in which the wafer support pins 29 all have the same length).

[0348] Therefore, in this embodiment, contact between the edge of the semiconductor wafer 7 and the wafer hook 17 or a portion of the measurement chamber 3 (eg, the cover 15 or the body 19 ) or another portion of the apparatus 1 can be prevented.

[0349] In this embodiment, the distance between each wafer support pin 29 and the center of the balance plate 27 (when the balance plate 27 is viewed perpendicularly to the main plane, main surface or main face of the balance plate 27) is not particularly limited and may be different from that of the comparative example.

[0350] Figures 5(a) and 5(b) illustrate a balance pan 27 that can be used in the first embodiment of the present invention. Figure 5(a) illustrates the balance pan 27 when viewed perpendicular to the principal plane, principal surface, or principal face of the balance pan 27. Figure 5(b) illustrates the balance pan 27 as viewed from the side.

[0351] As shown in Figures 5(a) and 5(b), the balance plate 27 includes three wafer support pins 29 (exactly or only three wafer support pins 29), which include at least two wafer support pins 29 of different lengths. The wafer support pins 29 extend perpendicular to the main plane or main surface or main face of the balance plate 27.

[0352] The wafer support pins 29 are each connected to a respective arm 30 extending radially outwardly from a central region of the balance pan 27 (when viewing the balance pan 27 perpendicularly to its major plane or surface or face).

[0353] The three wafer support pins 29 may each have a different respective length (so that there are three wafer support pins 29 of different lengths).

[0354] 6 and 7 show a device 31 according to a second embodiment of the invention.

[0355] Device 31 is a modified version of Device 1 shown in Figures 1 and 2 and described above as a comparative example. Device 31 may therefore include any features shown in Figures 1 and 2 and / or described above as a comparative example, unless they are incompatible with and / or replaced by the modifications described below. Corresponding features are denoted by the same reference numerals in Figures 6 and 7 .

[0356] Specifically, as described below, apparatus 31 differs from apparatus 1 of the comparative example in that apparatus 31 has a balance pan 35 that is different from balance pan 11 of apparatus 1. Any other features (one, more than one, or all) of apparatus 31 may be the same as apparatus 1 of the comparative example.

[0357] Specifically, in apparatus 31, the weighing device 5 of apparatus 1 of the comparative example is replaced with a weighing device 33 having a balance pan 35 different from the balance pan 11 of weighing device 5. Any other features (one, more than one, or all) of weighing device 33 may be the same as those of weighing device 5 of apparatus 1. For example, weighing device 33 includes the same load cell 9 as weighing device 5 and may include the same plurality of legs 21 as weighing device 5.

[0358] The balance plate 35 includes a plurality of wafer support pins 37. The wafer support pins 37 extend perpendicularly to the main plane, main surface, or main face of the balance plate 35. Specifically, when the semiconductor wafer 7 is loaded on the balance plate 35, the wafer support pins 37 extend perpendicularly to the main plane, main surface, or main face of the semiconductor wafer 7 from the side of the balance plate 35.

[0359] In this embodiment, the balance plate 35 includes three wafer support pins 37 (exactly or only three wafer support pins 37). Of course, in other embodiments, there may be a different number of wafer support pins 37. For example, in other embodiments, there may be three or more wafer support pins 37.

[0360] The wafer support pins 37 are configured to contact the lower side of the semiconductor wafer 7 loaded on the balance pan 35 to support the semiconductor wafer 7 during weight measurement.

[0361] As in the comparative example, in this embodiment, the load cell 9 is not horizontal. In other words, the weighing axis of the load cell 9 may not be vertical, and / or the top and / or bottom surfaces of the load cell 9 (and / or the housing surrounding the load cell 9) may not be horizontal.

[0362] Since the load cell 9 is not horizontal, the balance pan 35 coupled or connected to the load cell 9 is also not horizontal. In other words, when the semiconductor wafer 7 is loaded on the balance pan 35, the main plane or main surface or main face of the balance pan 35 facing the semiconductor wafer 7 is not horizontal or horizontal.

[0363] For example, because the load cell 9 is not horizontal, the axis of the balance pan 35 connected to the load cell 9 may not be vertical, so the main plane or main surface or main face of the balance pan 35 may not be horizontal or horizontal.

[0364] However, in this embodiment, the wafer support pins 37 include at least two wafer support pins 37 of different lengths. In other words, the distances that the wafer support pins 37 extend perpendicularly from the main plane, main surface, or main face of the balance plate 35 include at least two different distances. For example, each wafer support pin 37 may have a different length and extend perpendicularly from the main plane, main surface, or main face of the balance plate 35 by a different distance.

[0365] There may be three wafer support pins 37, and each of the three wafer support pins 37 may have a different respective length.

[0366] Each wafer support pin 37 may have a fixed length. Alternatively, one or more wafer support pins 37 may have an adjustable length.

[0367] The length of the wafer support pin 37 can be configured so that the top of the wafer support pin 37 is roughly or substantially arranged on the transverse plane, or on a roughly transverse plane (for example, a plane inclined less than 5 degrees relative to the transverse plane), or on a plane that is more horizontal and / or closer to the transverse plane than the main plane or main surface or main surface of the balance plate 35.

[0368] The plane formed by the top of the wafer support pin 37 (or the best fit plane fitted to the top of the wafer support pin 37) may be more horizontal / closer to horizontal (or horizontal) than the plane formed by the bottom of the wafer support pin 37 or the main plane or main surface or main face of the balance plate 35.

[0369] Compared to an example in which all wafer support pins 37 have the same length, wafer support pins 37 of different lengths can support the wafer 7 in a more horizontal and / or more lateral direction.

[0370] Therefore, when the semiconductor wafer 7 is loaded on the weighing device 33, the semiconductor wafer is closer to horizontal or closer to lateral orientation than in the comparative example.

[0371] Generally speaking, the length of the wafer support pins 37 can be configured and / or arranged and / or selected to support the semiconductor wafer 7 in a more horizontal (or lateral), or substantially horizontal (or lateral), or horizontal (or lateral) orientation (compared to an example where the wafer support pins all have the same length).

[0372] Therefore, in this embodiment, contact between the edge of the semiconductor wafer 7 and the wafer hook 17 or a portion of the measurement chamber 3 (eg, the cover 15 or the body 19 ) or another portion of the apparatus 1 can be prevented.

[0373] Furthermore, in this embodiment, the balance plate 35 is configured so that the wafer support pins 37 contact the underside of the semiconductor wafer 7 near the edge (eg, outer circumferential edge or peripheral edge) of the semiconductor wafer 7 or closer to the edge of the semiconductor wafer 7 than in the previous example.

[0374] For example, the balance plate 35 can be configured so that each wafer support pin 37 contacts the underside of the semiconductor wafer 7 at a distance less than or equal to 100 mm, or 90 mm, or 80 mm, or 75 mm, or 70 mm, or 60 mm, or 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from the edge of the semiconductor wafer 7 (for a wafer with a diameter of 300 mm).

[0375] In reality, semiconductor wafers are often not flat. For example, they may have a curved or bowed shape. When the semiconductor wafer is supported near the center of the semiconductor wafer, as in the comparative example discussed above, this introduces considerable uncertainty regarding the position of the semiconductor wafer's edge. As discussed above, the deviation between the expected position of the semiconductor wafer's edge when the semiconductor wafer is horizontal or in a landscape orientation and the actual position of the semiconductor wafer's edge can lead to inaccurate weight measurements performed by the weighing device.

[0376] In this embodiment, the semiconductor wafer 7 is supported near its edge. Therefore, even if the semiconductor wafer 7 is bent or bowed, the edge position of the semiconductor wafer 7 can still be controlled and / or clearly defined. This can prevent or reduce the problems discussed above.

[0377] As described above, a significant discrepancy between the expected edge position of the semiconductor wafer 7 when the semiconductor wafer 7 is horizontal or in a landscape orientation and the actual edge position of the semiconductor wafer 7 can occur. This can cause the edge of the semiconductor wafer 7 to contact one or more wafer hooks 17 when the semiconductor wafer 7 is placed on the balance pan 11. This means that part of the weight of the semiconductor wafer 7 is supported by one or more wafer hooks 17, and the weight measurement can be inaccurate.

[0378] Therefore, in this embodiment, the wafer support pins 37 can be configured to contact the underside of the semiconductor wafer 7 (when the semiconductor wafer 7 is supported by the balance plate 35) at a position close to where the wafer hook 17 contacts the underside of the semiconductor wafer 7 (when the semiconductor wafer 7 is supported by the wafer hook 17). Thus, the edge position of the semiconductor wafer 7 is controlled and / or clearly defined at the position of the wafer hook 17, thereby reducing or preventing contact between the edge of the semiconductor wafer 7 and the wafer hook 17 when the semiconductor wafer 7 is loaded on the balance plate 35.

[0379] Figures 8(a) and 8(b) illustrate a balance pan 35 that can be used in the second embodiment of the present invention. Figure 8(a) shows the balance pan 35 when viewed perpendicular to the main plane, main surface, or main face of the balance pan 35. Figure 8(b) shows the balance pan 35 viewed from the side.

[0380] As shown in Figures 8(a) and 8(b), the balance plate 35 includes three wafer support pins 37 (exactly or only three wafer support pins 37), which include at least two wafer support pins 37 of different lengths. The wafer support pins 37 extend perpendicular to the main plane or main surface or main face of the balance plate 35.

[0381] Wafer support pins 37 are each connected to a respective arm 30 extending radially outward from a central region of balance pan 35 (when viewing balance pan 35 perpendicular to its major plane or surface or face).

[0382] The three wafer support pins 37 may each have a different respective length (so that there are three wafer support pins 37 of three different lengths).

[0383] FIG9 shows an apparatus 39 according to a third embodiment of the present invention. Apparatus 39 is a modified version of apparatus 1 shown in FIG1 and FIG2 and described above as a comparative example. Apparatus 39 may therefore have any of the features shown in FIG1 and FIG2 and / or described above as a comparative example, unless such features are incompatible with and / or replaced by the modifications described below.

[0384] Specifically, as described below, apparatus 39 differs from apparatus 1 of the comparative example in that apparatus 39 has a balance pan 43 that is different from balance pan 11 of apparatus 1. Any other features (one, more than one, or all) of apparatus 39 may be the same as those of apparatus 1 of the comparative example. Corresponding features are denoted by the same reference numerals in FIG. 9 .

[0385] Specifically, in apparatus 39, the weighing device 5 of apparatus 1 of the comparative example is replaced with a weighing device 41 having a balance pan 43 that is different from the balance pan 11 of weighing device 5. Any other features (one, more than one, or all) of weighing device 41 may be the same as those of weighing device 5 of apparatus 1. For example, weighing device 41 includes the same load cell 9 as weighing device 5 and may include the same plurality of legs 21 as weighing device 5.

[0386] The balance plate 43 includes a plurality of wafer support pins 45. The wafer support pins 45 extend perpendicularly to the main plane, main surface, or main face of the balance plate 43. Specifically, when the semiconductor wafer 7 is loaded on the balance plate 43, the wafer support pins 45 extend perpendicularly to the main plane, main surface, or main face of the semiconductor wafer 7 from the side of the balance plate 43.

[0387] In this embodiment, the balance plate 43 includes three wafer support pins 45 (exactly or only three wafer support pins 45). Of course, in other embodiments, there may be a different number of wafer support pins 45. For example, in other embodiments, there may be three or more wafer support pins 45.

[0388] The wafer support pins 45 are configured to contact the lower side of the semiconductor wafer 7 loaded on the balance pan 43 to support the semiconductor wafer 7 during weight measurement.

[0389] In this embodiment, the wafer support pins 45 all have the same length (or substantially the same length).

[0390] For example, in this embodiment, the load cell 9 can be horizontal so that the balance pan 43 is horizontal.

[0391] As in the second embodiment, in this embodiment, the balance plate 43 is configured so that the wafer support pins 45 contact the underside of the semiconductor wafer 7 near the edge (eg, outer circumferential edge or peripheral edge) of the semiconductor wafer 7 .

[0392] For example, the balance plate 43 can be configured so that each wafer support pin 45 contacts the underside of the semiconductor wafer 7 at a distance less than or equal to 100 mm, or 90 mm, or 80 mm, or 75 mm, or 70 mm, or 60 mm, or 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from the edge of the semiconductor wafer 7 (for a wafer with a diameter of 300 mm).

[0393] For example, the balance plate 43 can be configured so that each wafer support pin 45 is located at least 50 mm, or at least 60 mm, or at least 70 mm, or at least 80 mm, or at least 90 mm, or at least 100 mm, or at least 110 mm, or at least 120 mm, or at least 130 mm, or at least 140 mm from the center of the support (for a wafer with a diameter of 300 mm).

[0394] Additionally, like the second embodiment, in this embodiment, the wafer support pins 45 may be configured to contact the underside of the semiconductor wafer 7 at a position close to where the wafer hooks 17 contact the underside of the semiconductor wafer 7 (when the semiconductor wafer 7 is supported by the wafer hooks 17 ).

[0395] Figures 10(a) and 10(b) illustrate a balance pan 43 that can be used in the third embodiment of the present invention. Figure 10(a) shows the balance pan 43 when viewed perpendicular to the main plane, main surface, or main face of the balance pan 43. Figure 10(b) shows the balance pan 43 viewed from the side.

[0396] As shown in Figures 10(a) and 10(b), the balance plate 43 includes three wafer support pins 45 (exactly or only three wafer support pins 45), all of which have the same length. The wafer support pins 45 extend perpendicular to the main plane or main surface or main face of the balance plate 43.

[0397] Wafer support pins 45 are each connected to a respective arm 30 extending radially outward from a central region of balance pan 43 (when viewing balance pan 43 perpendicular to its major plane or surface).

[0398] Figures 11(a) and 11(b) illustrate a cover that can be used for a measurement chamber in an embodiment of the present invention. The cover shown in Figures 11(a) and 11(b) may correspond to the cover in any of the above-described embodiments, such as the cover 15 in any of Figures 1 to 10.

[0399] The cover member shown in Figures 11(a) and 11(b) can be used as the cover member in any of the above embodiments.

[0400] 11( a ) and 11 ( b ), the cover 15 includes three wafer hooks 17 (exactly or only three wafer hooks 17 ) for supporting the wafer 7 . The cover 15 and the wafer hooks 17 may have any of the features of the cover 15 and the wafer hooks 17 described above.

[0401] The three wafer hooks 17 are evenly distributed around the circumference of the wafer 7 , for example, to form an equilateral triangle between the three wafer hooks 17 .

[0402] In particular, the contact points of the three wafer hooks 17 that contact and support the wafer 7 may be evenly distributed around the circumference of the wafer 7, for example, to form an equilateral triangle between the contact points of the three wafer hooks 17.

[0403] The wafer hook 17 is substantially L-shaped and extends inward relative to the wafer 7 .

[0404] In particular, in this embodiment, each wafer hook 17 includes a first portion extending substantially vertically downward from the underside of the cover 15 , and a second portion extending substantially laterally from the first portion and radially inward relative to the wafer 7 .

[0405] Of course, in other embodiments, the second portion of one or more wafer hooks 17 may not extend radially inward. For example, the second portion of one or more wafer hooks 17 may form an acute angle with the radial direction of the wafer.

[0406] In one embodiment, the second portion of the first wafer hook 17 may be in the radial direction of the wafer, and the second portions of the second and third wafer hooks 17 may be perpendicular to the second portion of the first wafer hook 17 .

[0407] The second portion of the wafer hooks 17 is long enough to allow the wafer 7 to be inserted between any two wafer hooks 17 from the side (i.e., laterally) and then lowered onto the second portion of the wafer hooks 17. For example, the wafer 7 may be supported from below by an end effector or other wafer support member, and the end effector may be used to position the wafer 7 between the wafer hooks 17 and lower the wafer 7 onto the second portion of the wafer hooks 17.

[0408] The wafer hooks 17 may each include a protrusion, such as a bump or pin, for contacting the underside of the wafer 7 when the wafer 7 is supported by the wafer hook 17. This minimizes contact between the wafer 7 and the wafer hook 17, thereby minimizing contamination of the wafer 7. For example, the protrusion may be located on the upper side of the second portion of the wafer hook 175.

[0409] The features disclosed in the preceding description, or in the following claims, or in the accompanying drawings (appropriately expressed in their specific form, or in the form of means for performing the disclosed function, or methods or processes for obtaining the disclosed results) may be used independently or in any combination of these features to implement different forms of the present invention.

[0410] While the present invention has been described with reference to the exemplary embodiments described above, numerous equivalent modifications and variations will be apparent to those skilled in the art given the present invention. Accordingly, the exemplary embodiments of the present invention described above are to be considered illustrative rather than restrictive. Numerous changes may be made to the described embodiments without departing from the spirit and scope of the present invention.

[0411] For the avoidance of doubt, any theoretical explanations provided herein are intended to enhance the reader's understanding. The inventors do not wish to be bound by any such theoretical explanations.

[0412] Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0413] Throughout this specification, including the claims that follow, unless the context requires otherwise, the words “comprise” and “comprising” and variations such as “including” and “comprising” will be understood to imply the inclusion of a stated integer or step or group or plurality of steps but not the exclusion of any other integer or step or group or plurality of steps.

[0414] It should be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when a value is expressed as an approximation by using the antecedent "about," it will be understood that the particular value forms another embodiment. The term "about" in relation to a numerical value is optional and means, for example, + / - 10%.

[0415] Other aspects and / or embodiments of the present invention are described in the following numbered items.

[0416] 1. A weighing device for measuring the weight of a wafer having a specific diameter D, the weighing device comprising a support for supporting the wafer during weight measurement, wherein: The support includes a plurality of contact elements configured to contact the underside of the wafer at a distance less than or equal to D / 3 from the edge of the wafer to support the wafer during weight measurement.

[0417] 2. The weighing device according to item 1, wherein the plurality of contact elements are configured to contact the underside of the wafer at a distance less than or equal to D / 4, or D / 5, or D / 6, or D / 7, or D / 8, or D / 9, or D / 10, or D / 11, or D / 12, or D / 13, or D / 14, or D / 15, or D / 16, or D / 17, or D / 18, or D / 19, or D / 20 from the edge of the wafer.

[0418] 3. A weighing device according to item 1 or 2, wherein the plurality of contact elements include pins.

[0419] 4. A weighing device according to any one of the preceding items, wherein the weighing device is used to measure the weight of a wafer having a diameter of 200 mm, or 300 mm, or 450 mm.

[0420] 5. A weighing device according to any one of the preceding items, wherein the plurality of contact elements comprises two or more contact elements of different lengths.

[0421] 6. The weighing device according to item 5, wherein the plurality of contact elements comprises two or more contact elements of different lengths to support the wafer in a more horizontal direction.

[0422] 7. A weighing device according to any one of the preceding clauses, wherein one or more of the plurality of contact elements has an adjustable length.

[0423] 8. An equipment, including: A weighing device according to any of the preceding clauses; and a plurality of wafer support elements for supporting the wafer from below while the wafer is being loaded onto the support; One of the plurality of contact elements is configured to contact the underside of the wafer at a distance less than or equal to 50 mm from a position where one of the plurality of wafer support elements is configured to contact the underside of the wafer.

[0424] 9. The apparatus of item 8, wherein the contact element is configured to contact the underside of the wafer at a distance of less than or equal to 40 mm, or 30 mm, or 20 mm, or 10 mm from the position where the wafer support element is configured to contact the underside of the wafer.

[0425] 10. An apparatus according to item 8 or item 9, wherein each of the plurality of contact elements is configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a position at which one of the plurality of wafer support elements is configured to contact the underside of the wafer.

[0426] 11. The apparatus of any one of items 8 to 10, wherein: The apparatus comprises a measuring chamber having a cover; The weighing device is within the measuring chamber; and The plurality of wafer support elements are attached to the cover.

[0427] 12. The apparatus according to item 11, wherein the apparatus is configured so that when the cover is positioned on the measurement chamber, the wafer is loaded from the wafer support element onto the support.

[0428] 13. A weighing device for measuring the weight of a wafer, the weighing device comprising a support for supporting the wafer during weight measurement, wherein: The support includes a plurality of contact elements located at least 50 mm from the center of the support and configured to contact the underside of the wafer to support the wafer during weight measurement.

[0429] 14. A weighing device according to item 13, wherein the plurality of contact elements are located at a distance of at least 60 mm, or at least 70 mm, or at least 75 mm, or at least 80 mm, or at least 90 mm, or at least 100 mm, or at least 110 mm, or at least 120 mm, or at least 130 mm, or at least 140 mm from the center of the support.

[0430] 15. An equipment comprising: A weighing device for performing weight measurement on a wafer, the weighing device comprising a support for supporting the wafer during weight measurement, wherein the support comprises a plurality of contact elements configured to contact an underside of the wafer to support the wafer during weight measurement; and a plurality of wafer support elements for supporting the wafer from below while the wafer is being loaded onto the support; One of the plurality of contact elements is configured to contact the underside of the wafer at a distance less than or equal to 50 mm from a position where one of the plurality of wafer supporting elements is configured to contact the underside of the wafer.

[0431] 16. The apparatus of item 15, wherein the contact element is configured to contact the underside of the wafer at a distance of less than or equal to 40 mm, or 30 mm, or 20 mm, or 10 mm from the position where the wafer support element is configured to contact the underside of the wafer.

[0432] 17. An apparatus according to item 15 or 16, wherein each of the plurality of contact elements is configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a position at which one of the plurality of wafer support elements is configured to contact the underside of the wafer.

[0433] 18. An apparatus according to any one of items 15 to 17, wherein the plurality of contact elements comprises pins.

[0434] 19. The apparatus of any one of items 15 to 18, wherein the plurality of contact elements comprises two or more contact elements of different lengths.

[0435] 20. The apparatus of item 19, wherein the plurality of contact elements comprises two or more contact elements of different lengths to support the wafer in a more horizontal orientation during weight measurement.

[0436] 21. An apparatus according to any one of items 15 to 20, wherein one or more of the plurality of contact elements has an adjustable length.

[0437] 22. The apparatus of any one of items 15 to 21, wherein: The weighing device is used to measure the weight of a wafer having a specific diameter D; and One or more of the plurality of contact elements are configured to contact the underside of the wafer at a distance less than or equal to D / 4, or D / 5, or D / 6, or D / 7, or D / 8, or D / 9, or D / 10, or D / 11, or D / 12, or D / 13, or D / 14, or D / 15, or D / 16, or D / 17, or D / 18, or D / 19, or D / 20 from the edge of the wafer.

[0438] 23. An apparatus according to any one of items 15 to 22, wherein one or more of the plurality of contact elements is located at a distance of at least 50 mm, or at least 60 mm, or at least 70 mm, or at least 75 mm, or at least 80 mm, or at least 90 mm, or at least 100 mm, or at least 110 mm, or at least 120 mm, or at least 130 mm, or at least 140 mm from the center of the support.

[0439] 24. The apparatus of any one of items 15 to 23, wherein: The apparatus comprises a measuring chamber having a cover; The weighing device is within the measuring chamber; and A plurality of wafer support elements are attached to the cover.

[0440] 25. The apparatus of item 24, wherein the apparatus is configured such that when the cover is positioned on the measurement chamber, the wafer is loaded from the wafer support element onto the support.

[0441] 26. A weighing device for measuring the weight of a wafer, the weighing device comprising a support for supporting the wafer during weight measurement, wherein: The support includes a plurality of contact elements configured to contact the underside of the wafer to support the wafer during weight measurement; and The plurality of contact elements includes two or more contact elements of different lengths.

[0442] 27. The weighing device of item 26, wherein the plurality of contact elements comprises two or more contact elements of different lengths to support the wafer in a more horizontal orientation during weight measurement.

[0443] 28. An apparatus according to item 26 or 27, wherein at least one of the plurality of contact elements has an adjustable length.

[0444] 29. A weighing device for measuring the weight of a wafer, the weighing device comprising a support for supporting the wafer during weight measurement, wherein: The support includes a plurality of contact elements configured to contact the underside of the wafer to support the wafer during weight measurement; and At least one of the plurality of contact elements has an adjustable length.

[0445] 30. A method comprising: Performing weight measurement on wafers with a specific diameter D; The method includes supporting the wafer from below at a distance less than or equal to D / 3 from the edge of the wafer during weight measurement.

[0446] 31. A method comprising: A weighing device for performing weight measurement on a wafer is provided, the weighing device comprising a support for supporting the wafer during weight measurement, the support comprising a plurality of contact elements configured to contact an underside of the wafer to support the wafer during weight measurement; The method includes setting the length of the plurality of contact elements to support the wafer in a more horizontal orientation during weight measurement.

[0447] 1: Equipment 3: Measurement chamber 5: Weighing device 7: Semiconductor wafer 9: Load cell 11: Balance Plate 13: Wafer support pin 15: Cover 17: Wafer hook 19: Subject 21: Support legs 22: Controller 23: Equipment 25: Weighing device 27: Balance Plate 29: Wafer support pin 30: Arm 31: Equipment 33: Weighing device 35: Balance Plate 37: Wafer support pin 39: Equipment 41: Weighing device 43: Balance Plate 45: Wafer support pin

Claims

1. A measuring device, comprising: A measuring chamber having a removable cover; And a plurality of wafer support elements for supporting a wafer from below, wherein the plurality of wafer support elements are provided on the cover.

2. The device as claimed in claim 1, wherein the wafer support elements are provided on one of the lower sides of the cover.

3. The device as described in claim 1 or 2, wherein the wafer support elements are wafer hooks.

4. The device as described in any one of claims 1 to 2, wherein exactly three of the wafer support elements are present.

5. The apparatus of claim 4, wherein the contact points of the three wafer support elements are configured to be evenly spaced around the circumference of the wafer when the wafer is supported by the three wafer support elements.

6. The device as claimed in claim 1 or 2, wherein the cover is one of the top surfaces of the measuring chamber.

7. The device as claimed in claim 1 or 2, wherein the cover is vertically upward movable relative to a body of the measuring chamber to remove the cover from the body of the measuring chamber, and is vertically downward movable relative to the body of the measuring chamber to position the cover on the body of the measuring chamber.

8. The device as claimed in claim 7, wherein the device includes one or more actuators connected or coupled to the cover and operable to move the cover relative to the body of the measuring chamber.

9. The apparatus as claimed in claim 1 or 2, wherein the wafer support elements are configured to suspend the wafer below the cover.

10. The device as described in claim 1 or 2, wherein: The device includes a weighing device for measuring the weight of a wafer; and the weighing device is located in the measuring chamber.

11. The apparatus as claimed in claim 10, wherein the apparatus is configured such that when the cover is positioned on the measuring chamber, the wafer is loaded from the wafer support elements onto the weighing device.

12. The device as described in claim 10, wherein: The weighing device includes a support for supporting the wafer during the weight measurement; and the device is configured such that the wafer is loaded from the wafer support elements onto the support when the cover is positioned on the measurement chamber.

13. The apparatus of claim 12, wherein the support includes a plurality of contact elements configured to contact one of the undersides of the wafer during the weight measurement to support the wafer.

14. The device as claimed in claim 13, wherein when the cover is positioned on the measuring chamber, the contact points of the contact elements are higher in the vertical direction than the contact points of the wafer support elements.

15. The device as claimed in claim 1 or 2, wherein the device includes a seal located between the cover and the measuring chamber when the cover is positioned on the measuring chamber.

16. The apparatus as claimed in claim 1 or 2, wherein each of the plurality of wafer supports is substantially L-shaped.

17. The apparatus as claimed in claim 1 or 2, wherein each of the plurality of wafer support elements is configured to extend inward relative to one of the wafers supported by the plurality of wafer support elements.

18. The apparatus of claim 10, wherein the weighing device is used to weigh a wafer having a specific diameter D, the weighing device including a support for supporting the wafer during the weight measurement, wherein: the support includes a plurality of contact elements configured to contact a lower side of the wafer at a distance less than or equal to D / 3 from one edge of the wafer to support the wafer during the weight measurement.

19. The apparatus of claim 18, wherein the plurality of contact elements are configured to contact the underside of the wafer at a distance less than or equal to D / 4, or D / 5, or D / 6, or D / 7, or D / 8, or D / 9, or D / 10, or D / 11, or D / 12, or D / 13, or D / 14, or D / 15, or D / 16, or D / 17, or D / 18, or D / 19, or D / 20 from the edge of the wafer.

20. The device as claimed in claim 18, wherein the plurality of contact elements includes pins.

21. The apparatus as claimed in claim 18, wherein the weighing device is used for weighing a wafer having one of a diameter of 200 mm, 300 nm, or 450 mm.

22. The device as claimed in claim 18, wherein the plurality of contact elements comprises two or more contact elements of different lengths.

23. The device as claimed in claim 22, wherein the plurality of contact elements includes two or more contact elements of different lengths to support the wafer in a more horizontal orientation.

24. The device as claimed in claim 18, wherein one or more of the plurality of contact elements have an adjustable length.

25. The device as described in claim 18, wherein: The plurality of wafer support elements are used to support the wafer from below when the wafer is being loaded onto the support; and one of the plurality of contact elements is configured to contact the underside of the wafer at a distance of less than or equal to 50 mm from the position where one of the plurality of wafer support elements is configured to contact the underside of the wafer.

26. The device as claimed in claim 25, wherein the contact element is configured to contact the underside of the wafer at a distance of less than or equal to 40 mm, or 30 mm, or 20 mm, or 10 mm from a position where the wafer support element is configured to contact the underside of the wafer.

27. The apparatus of claim 25, wherein each of the plurality of contact elements is configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a position where one of the plurality of wafer support elements is configured to contact the underside of the wafer.

28. The apparatus as claimed in claim 10, wherein the weighing device includes a support for supporting the wafer during the weight measurement, wherein: The support includes a plurality of contact elements located at a distance of at least 50 mm from the center of one of the supports and configured to contact the underside of one of the wafers during the weight measurement to support the wafer.

29. The device as claimed in claim 28, wherein the plurality of contact elements are located at a distance of at least 60 mm, or at least 70 mm, or at least 75 mm, or at least 80 mm, or at least 90 mm, or at least 100 mm, or at least 110 mm, or at least 120 mm, or at least 130 mm, or at least 140 mm from the center of the support.

30. The device as described in claim 10, wherein: The weighing device includes a support member for supporting the wafer during the weight measurement, wherein the support member includes a plurality of contact elements configured to contact one of the lower sides of the wafer during the weight measurement to support the wafer; and the plurality of wafer support elements are configured to support the wafer from below as the wafer is being loaded onto the support member; and one of the contact elements is configured to contact the lower side of the wafer at a distance of less than or equal to 50 mm from the position where one of the wafer support elements is configured to contact the lower side of the wafer.

31. The device as claimed in claim 30, wherein the contact element is configured to contact the underside of the wafer at a distance of less than or equal to 40 mm, or 30 mm, or 20 mm, or 10 mm from a position where the wafer support element is configured to contact the underside of the wafer.

32. The device as claimed in claim 30, wherein each of the plurality of contact elements is configured to contact the underside of the wafer at a distance of less than or equal to 50 mm, or 40 mm, or 30 mm, or 20 mm, or 10 mm from a position where one of the plurality of wafer support elements is configured to contact the underside of the wafer.

33. The device as claimed in claim 30, wherein the plurality of contact elements includes pins.

34. The device as claimed in claim 30, wherein the plurality of contact elements comprises two or more contact elements of different lengths.

35. The apparatus as claimed in claim 34, wherein the plurality of contact elements includes two or more contact elements of different lengths to support the wafer in a more horizontal orientation during the weight measurement.

36. The device as claimed in claim 30, wherein one or more of the plurality of contact elements has an adjustable length.

37. The device as described in claim 30, wherein: The weighing device is used to measure the weight of a wafer having a specific diameter D; and one or more of the plurality of contact elements are configured to contact the underside of one of the wafers at a distance less than or equal to D / 3, or D / 4, or D / 5, or D / 6, or D / 7, or D / 8, or D / 9, or D / 10, or D / 11, or D / 12, or D / 13, or D / 14, or D / 15, or D / 16, or D / 17, or D / 18, or D / 19, or D / 20 from the edge of one of the wafers.

38. The device as claimed in claim 30, wherein one or more of the plurality of contact elements are located at a distance of at least 50 mm, or at least 60 mm, or at least 70 mm, or at least 75 mm, or at least 80 mm, or at least 90 mm, or at least 100 mm, or at least 110 mm, or at least 120 mm, or at least 130 mm, or at least 140 mm from the center of one of the supports.

39. The apparatus as claimed in claim 10, wherein the weighing device includes a support for supporting the wafer during the weight measurement, wherein: The support includes a plurality of contact elements configured to contact one of the undersides of the wafer during the weight measurement to support the wafer; and the plurality of contact elements includes two or more contact elements of different lengths.

40. The apparatus of claim 39, wherein the plurality of contact elements comprises two or more contact elements of different lengths to support the wafer in a more horizontal orientation during the weight measurement.

41. The device as claimed in claim 39, wherein at least one of the plurality of contact elements has an adjustable length.

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