Resistivity detection device and resistivity detection method for epitaxial wafer

Abstract

The invention provides a resistivity detection device and method for an epitaxial wafer, and the device comprises a desorption chamber which is internally provided with a first bearing platform for bearing the epitaxial wafer; a second bearing table used for bearing an epitaxial wafer is arranged in the first ultraviolet light chamber; a third bearing table used for bearing an epitaxial wafer is arranged in the second ultraviolet light chamber; the measuring unit is used for measuring the epitaxial wafer to obtain the resistivity of the epitaxial wafer; wherein at least one of the first bearing table, the second bearing table and the third bearing table is configured to be a rotating bearing table, and the rotating bearing table can bear the epitaxial wafer and drive the epitaxial wafer to rotate in the circumferential direction. The invention provides a resistivity detection device and a resistivity detection method of an epitaxial wafer. The resistivity detection accuracy of the epitaxial wafer can be improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing technology, and in particular to a resistivity detection device and a resistivity detection method for an epitaxial wafer. Background Art

[0002] With the development of integrated circuit manufacturing technology, the requirements for the resistivity measurement accuracy of epitaxial wafers are getting higher and higher. Epitaxial wafers are key materials for semiconductor device manufacturing, and the accuracy of their resistivity directly affects the performance and reliability of the device. Therefore, the development of high-precision epitaxial wafer resistivity measurement technology is crucial to the semiconductor industry. Resistivity, as an important parameter to measure the electrical properties of epitaxial wafers, is inversely proportional to conductivity, and its size mainly depends on temperature, pressure and doping concentration.

[0003] At present, the resistivity measurement of epitaxial wafers mainly adopts non-contact measurement technology. This technology obtains the resistivity information of the wafer by inducing an AC electric field on the surface of the wafer and measuring the photovoltage change caused by doping. When measuring the resistivity of epitaxial wafers, the oxide film generated on the epitaxial wafer may be uneven, resulting in insufficient precision in the resistivity measurement of the epitaxial wafer. Summary of the invention

[0004] In order to solve at least one technical problem in the above-mentioned prior art, the embodiments of the present disclosure provide a resistivity detection device and a resistivity detection method for an epitaxial wafer.

[0005] The technical solutions provided by the embodiments of the present disclosure are as follows:

[0006] In a first aspect, an embodiment of the present disclosure provides a resistivity detection device for an epitaxial wafer, comprising:

[0007] A desorption chamber, wherein a first supporting platform for supporting the epitaxial wafer is provided inside the desorption chamber;

[0008] A first ultraviolet light chamber, wherein a second carrying platform for carrying the epitaxial wafer is provided inside the first ultraviolet light chamber;

[0009] a second ultraviolet light chamber, wherein a third carrying platform for carrying the epitaxial wafer is disposed inside the second ultraviolet light chamber; and

[0010] A measuring unit, used for measuring the epitaxial wafer to obtain the resistivity of the epitaxial wafer;

[0011] Wherein, at least one of the first carrier platform, the second carrier platform and the third carrier platform is constructed as a rotating carrier platform, and the rotating carrier platform can carry the epitaxial wafer and drive the epitaxial wafer to rotate circumferentially.

[0012] Exemplarily, the rotating support platform includes:

[0013] A susceptor for supporting epitaxial wafers; and

[0014] A support frame is supported under the base, the support frame includes a rotating spindle rotatable around its own axis, and a plurality of support arms extending radially outward and axially upward from the longitudinal axis of the rotating spindle, the support arm includes a first end and a second end opposite to each other in the axially upward extension direction thereof, the first end supports the base, the second end is connected to the rotating spindle, and the support arm can rotate synchronously with the rotating spindle.

[0015] Exemplarily, there are three support arms, and the three support arms are evenly distributed along the circumference of the rotating main shaft.

[0016] Exemplarily, the upper surface of the base is provided with a groove portion for supporting the epitaxial wafer, and the circumferential side wall of the groove portion includes a supporting portion for supporting an edge of the epitaxial wafer.

[0017] Exemplarily, the support portion is configured as an arc-shaped curved surface or an inclined surface.

[0018] Exemplarily, the first carrying platform, the second carrying platform and the third carrying platform are all configured as the rotating carrying platform.

[0019] Exemplarily, the desorption chamber further comprises:

[0020] A heating platform, disposed inside the desorption chamber and below the first supporting platform;

[0021] A metal partition is disposed above and around the supporting surface of the first supporting platform;

[0022] Wherein, when the first supporting platform is constructed as the rotating supporting platform, the supporting surface of the first supporting platform is arranged horizontally to drive the epitaxial wafer to rotate circumferentially in a horizontal plane.

[0023] Exemplarily, the structures of the first ultraviolet light chamber and the second ultraviolet light chamber are the same or different, and when the second carrier platform and the third carrier platform are configured as the rotating carrier platform, either the first ultraviolet light chamber or the second ultraviolet light chamber further comprises:

[0024] An ultraviolet lamp is arranged above the bearing surface of the rotating bearing platform;

[0025] A heat-insulating layer is arranged above the ultraviolet lamp;

[0026] The air inlet and the air outlet are respectively arranged on opposite sides of the rotating supporting platform along the radial direction of the epitaxial wafer carried by the rotating supporting platform; wherein the carrying surface of the rotating supporting platform is arranged horizontally to drive the epitaxial wafer to rotate circumferentially in the horizontal plane.

[0027] In a second aspect, the embodiments of the present disclosure further provide a resistivity detection method for an epitaxial wafer, which is applied to the resistivity detection device for the epitaxial wafer as described above, and the method comprises the following steps:

[0028] Place the epitaxial wafer on the second carrier of the first ultraviolet chamber, and perform a preheating treatment on the epitaxial wafer;

[0029] Carrying the epitaxial wafer on the first carrier of the desorption chamber, and performing a heating desorption process on the epitaxial wafer;

[0030] placing the epitaxial wafer on a third carrier of the second ultraviolet chamber to form an oxide film on the epitaxial wafer;

[0031] Placing the epitaxial wafer on a sample stage so that the oxide film forms a depletion layer under the interaction of charges;

[0032] Measuring the depletion layer to obtain the resistivity of the epitaxial wafer;

[0033] Among them, in the above steps, at least one of the first carrier platform, the second carrier platform and the third carrier platform is constructed as a rotating carrier platform, and during the corresponding processing of the epitaxial wafer, the epitaxial wafer is driven to rotate at a uniform speed in the circumferential direction by the rotating carrier platform.

[0034] Exemplarily, before placing the epitaxial wafer on a sample stage, the method further comprises: measuring the thickness of the oxide film.

[0035] The beneficial effects brought by the embodiments of the present disclosure are as follows:

[0036] In the resistivity detection device and resistivity detection method for epitaxial wafers provided in the embodiments of the present disclosure, at least one of the supporting platforms in the desorption chamber, the first ultraviolet light chamber and the second ultraviolet light chamber is constructed as a rotating supporting platform to drive the epitaxial wafer to rotate at a uniform circumferential speed during pre-treatment in the chamber, thereby reducing the risk of uneven oxide film growth caused by environmental factors in each chamber, thereby improving the uniformity of the oxide film required for resistivity detection of the epitaxial wafer, thereby improving the resistivity detection accuracy of the epitaxial wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram showing the temperature distribution inside the desorption chamber;

[0038] Figure 2 A schematic diagram showing the gas concentration distribution inside the UV chamber;

[0039] Figure 3 A schematic diagram showing the test results of an ellipsometer in the related art;

[0040] Figure 4 A schematic diagram showing the resistivity detection result of an epitaxial wafer in the related art;

[0041] Figure 5 A schematic diagram showing the structure of a resistivity detection device for an epitaxial wafer provided in an embodiment of the present disclosure;

[0042] Figure 6 A schematic diagram showing the structure of the first ultraviolet light chamber or the second ultraviolet light chamber in an embodiment of the present disclosure;

[0043] Figure 7 A schematic diagram showing the structure of a desorption chamber in an embodiment of the present disclosure;

[0044] Figure 8 A schematic diagram showing the structure of a rotating support platform in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0046] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0047] The features such as "parallel", "perpendicular", and "same" used in the embodiments of the present disclosure include the features such as "parallel", "perpendicular", and "same" in a strict sense, as well as the cases where "approximately parallel", "approximately perpendicular", "approximately the same", etc. include certain tolerances, taking into account the tolerances associated with the measurement of specific quantities (e.g., the limitations of the measurement system), and represent the acceptable deviation range for a specific value determined by ordinary technicians in the field. For example, "approximately" can mean within one or more standard deviations, or within 3% or 5% of the value.

[0048] In addition, in this document, unless otherwise defined, the terms "substantially", "substantially", "approximately" and "about" are used to describe and explain small changes. When used with an event or situation, these terms can cover situations where the event or situation occurs exactly, and can also cover situations where the event or situation occurs approximately. For example, when used with a numerical value, these terms can include a range of variation of less than or equal to 10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, less than or equal to ±0.05%. The term "substantially coplanar" can refer to two surfaces being arranged along the same plane in the micrometer range, for example, arranged along the same plane within 40μm, 30μm, 20μm, 10μm or 1μm.

[0049] Epitaxial wafer inspection equipment such as Semilab's QC-2500e / QC-3000e epitaxial wafer inspection platform is non-contact, non-destructive, high-yield, stable and reliable. This platform can provide powerful assistance for online monitoring of epitaxial process reaction chambers, pre-shipment testing of wafers, and incoming material inspection for IC manufacturing and process development.

[0050] QC-2500e / QC-3000e uses non-contact AC surface photovoltage technology to achieve non-destructive measurement, and can characterize the near-surface resistivity, near-surface doping concentration, and recombination lifetime of epitaxial growth process wafers. By measuring the surface depletion width, the resistivity changes in key areas of the wafer can be detected. The fully automated platform has the ability to support high-yield wafer production facilities, and can guarantee considerable yields even for comprehensive mapping of epitaxial wafer resistance distribution, in order to achieve the ability to monitor and control the epitaxial process. The equipment is mainly composed of a prealigner, a desorption chamber, an ultraviolet chamber 1 (UV1), an ultraviolet chamber 1 (UV2), and a three-dimensional sample platform (XYZ Sample stage).

[0051] Among them, the ultraviolet lamp in the UV chamber irradiates the surface of the epitaxial wafer in a chemical vapor deposition environment to ensure that the ozone above the wafer is uniform and dense, which can be quickly and evenly oxidized, and a layer of oxide film grows on the surface of the epitaxial wafer. The charge rods in the three-dimensional sample platform will scatter opposite charges on the surface of the oxide film. The interaction of the charges will cause a depletion layer on the surface of the epitaxial wafer. By measuring the width of the depletion layer and calculating it, the near-surface resistivity of the epitaxial wafer can be obtained. In actual production, it is easy to have inaccurate resistance measurements due to uneven growth of the oxide film, so the desorption chamber as a pre-treatment and the UV chamber for growing the oxide film are crucial.

[0052] Among them, the UV1 chamber and the UV2 chamber can be two completely identical UV chambers, and different parameters are set according to actual conditions, so that the UV1 chamber is used as a chamber for preheating the epitaxial wafer to remove adsorbed ions and molecules, and the UV2 chamber is used as a chamber for forming an oxide film on the epitaxial wafer.

[0053] The purpose of the desorption chamber is to remove adsorbed impurities on the wafer surface, which may affect subsequent process steps, such as oxide film growth or thin film deposition. The chamber usually achieves desorption by heating the wafer, that is, heating the wafer to a certain temperature so that the volatile molecules adsorbed on the wafer surface evaporate. At the same time, non-volatile impurities may also be removed.

[0054] The heating desorption process (Surface Layer Desorption) is to remove the charge associated with the ions and molecules adsorbed on the surface of the P-type epitaxial silicon wafer (SILICON) by heating it to about 200°C. It is also applicable to N-type wafers. The wafer is placed on three high-purity Al 2 O 3 The silicon surface is heated by a hot plate on a ceramic pin. This type of structure ensures high temperatures without causing backside contamination. The temperature is monitored by a J-type thermocouple sensor and controlled by a closed-loop proportional integral derivative (PID) controller. The temperature of the silicon surface is raised to the temperature required to remove (evaporate) the volatile molecules adsorbed on the surface. Volatile substances can also take away other non-volatile ions and molecules.

[0055] The oxide film required for corona charge is achieved by the in-situ UV lighting of the UV2 chamber. In the UV chamber, a low-pressure mercury discharge lamp illuminates the wafer uniformly in ambient air. The UV lamp radiation ionizes the oxygen naturally present in the air, making it more reactive with the epitaxial wafer. In order to provide the best oxidation process, the ambient air flows through a bubbling system, that is, oxygen-containing gas is input into the UV2 chamber, which increases the oxygen content in the air. Ultraviolet irradiation in oxygen-rich ambient air produces a natural oxide film of about in just a few minutes, which can meet accurate measurements. That is to say, the above-mentioned UV2 chamber will have an air inlet, through which the required gas is input into the UV2 chamber. The vapor deposition chamber is used below to represent the UV2 chamber.

[0056] When the epitaxial wafer enters the UV1 chamber for the removal of adsorbed ion molecules, the chamber temperature is low (about 35°C), the temperature inside the chamber is relatively uniform, and no other gases are introduced during the process, so the degree of treatment on the wafer surface is relatively consistent. However, when the wafer is transferred to the desorption chamber for the removal of volatile molecules after the UV1 chamber treatment, there is a certain temperature difference inside the desorption chamber due to the heat loss caused by the opening and closing of the door. Figure 1 FIG. 1 is a schematic diagram of temperature distribution in the desorption chamber, where A represents the side where the door 2 of the desorption chamber 1 is located. There is a certain temperature difference inside the desorption chamber, which will lead to inconsistent processing at both ends of the wafer, and the volatile molecules may not be completely processed in the area with weaker temperature.

[0057] In the UV2 chamber, UV radiation ionizes the oxygen naturally present in the air, making it more reactive with the silicon surface. To provide an optimal oxidation process, ambient air flows through a bubbling system, which increases the oxygen content of the air. UV irradiation in oxygen-rich ambient air produces approximately The natural oxide film can meet the requirements of accurate measurement. Although the chamber can meet the requirements of relatively uniform temperature, CDA gas is continuously introduced during the process to meet the requirements of oxide film growth. Due to the characteristics of the gas, the gas concentration inside the UV2 chamber is not consistent. Please refer to Figure 2 As shown, the gas concentrations on the side close to the gas injection side B and the side away from the gas injection side B in the UV chamber 3 are different, resulting in a certain difference in the thickness of the oxide film on the surface of the wafer.

[0058] The thickness of the oxide film grown in the resistivity detection device used in the prior art was measured by an ellipsometer. The measurement results are as follows: Figure 3 As shown in the figure, it is obvious that there is a large difference in the thickness of the oxide film at the top and bottom of the wafer, which is also the reason Figure 4 The specific reasons for the abnormality in the resistivity test result Map.

[0059] Based on this, the embodiments of the present disclosure provide a resistivity detection device and a resistivity detection method for an epitaxial wafer, which can improve the accuracy of resistivity detection.

[0060] like Figures 5 to 7 As shown, the resistivity detection device for an epitaxial wafer provided in an embodiment of the present disclosure includes:

[0061] A desorption chamber 100 , wherein a first supporting platform 110 for supporting the epitaxial wafer 10 is provided inside the desorption chamber 100 ;

[0062] A first ultraviolet light chamber 200 , wherein a second carrying platform 210 for carrying the epitaxial wafer 10 is disposed inside the first ultraviolet light chamber 200 ; and

[0063] A second ultraviolet light chamber 300 , wherein a third carrying platform 310 for carrying the epitaxial wafer 10 is provided inside the second ultraviolet light chamber 300 ;

[0064] At least one of the first carrier platform 110 , the second carrier platform 210 and the third carrier platform 310 is configured as a rotating carrier platform 20 , and the rotating carrier platform 20 is capable of carrying the epitaxial wafer 10 and driving the epitaxial wafer 10 to rotate circumferentially.

[0065] In the above scheme, by constructing at least one of the supporting platforms in the desorption chamber 100, the first ultraviolet light chamber 200 and the second ultraviolet light chamber 300 as a rotating supporting platform 20, the epitaxial wafer 10 is driven to rotate at a uniform speed in the circumferential direction during the pre-treatment process in the chamber, thereby reducing the risk of uneven growth of the oxide film caused by environmental factors in each chamber, thereby improving the uniformity of the oxide film required for resistivity detection of the epitaxial wafer 10, thereby improving the resistivity detection accuracy of the epitaxial wafer.

[0066] In some exemplary embodiments, Figure 6 and Figure 7 As shown, the first carrying platform 110 , the second carrying platform 210 and the third carrying platform 310 are all configured as the rotating carrying platform 20 .

[0067] In this way, during the pre-treatment process of preheating, heating for desorption and forming an oxide film on the wafer in sequence, the epitaxial wafer 10 in the corresponding first ultraviolet light chamber 200, the desorption chamber 100 and the second ultraviolet light chamber 300 rotates at a uniform speed in the circumferential direction driven by the rotating carrier 20, so that the epitaxial wafer 10 can continue to maintain a uniform rotation state during the pre-treatment process, ensuring that the epitaxial wafer 10 alternately receives temperature difference areas in the desorption chamber 100, which can ensure to a certain extent that the treatment degree of each position of the epitaxial wafer 10 is consistent, improve the uneven distribution caused by gas characteristics in the UV chamber, reduce the influence of gas concentration on the growth of the oxide film, ensure that the oxide film formed on the epitaxial wafer 10 is dense and uniform, and accurately measure the near-surface resistivity of the epitaxial wafer 10 by the surface photovoltage method.

[0068] As an exemplary embodiment, Figure 8 As shown, the rotating support platform 20 includes: a base 21 for supporting the epitaxial wafer 10; and a support frame 22 supported under the base 21; wherein the support frame 22 includes a rotating spindle 22a rotatable around its own axis, and a plurality of support arms 22b extending radially outward and axially upward from the longitudinal axis of the rotating spindle 22a, the support arm 22b includes a first end and a second end opposite to each other in the axially upward extension direction thereof, the first end supports the base 21, and the second end is connected to the rotating spindle 22a, and the support arm 22b can rotate synchronously with the rotating spindle 22a.

[0069] With the above solution, the rotating carrier 20 supports and fixes the epitaxial wafer 10 through the base 21, and the base 21 can be supported by a plurality of support arms 22b to keep the epitaxial wafer 10 horizontally arranged, and the rotating spindle 22a can drive the support arms 22b to rotate synchronously to achieve the circumferential rotation of the epitaxial wafer 10. This structure is simple and easy to implement. It is understandable that the specific structure of the rotating carrier 20 is not limited to this.

[0070] In addition, for example, Figure 8 As shown, there are three support arms 22 b, and the three support arms 22 b are evenly distributed along the circumference of the rotating spindle 22 a to ensure that the epitaxial wafer 10 can be stably supported during the pre-processing process.

[0071] It is understandable that the specific number and distribution of the support arms 22b are not limited thereto.

[0072] Furthermore, in some exemplary embodiments, Figure 8As shown, the upper surface of the base 21 is provided with a groove portion 21A for carrying the epitaxial wafer 10 , and the circumferential side wall 21B of the groove portion 21A includes a supporting portion for supporting the edge of the epitaxial wafer 10 .

[0073] With the above scheme, the base 21 carries the epitaxial wafer 10 by using the circumferential side walls 21B of the groove portion 21A on the surface of the base 21 to jointly support the edge of the epitaxial wafer 10. This method facilitates the loading and unloading of the epitaxial wafer 10, and the circumferential side walls 21B of the groove portion 21A can effectively limit the epitaxial wafer 10 to avoid the displacement of the epitaxial wafer 10 during rotation. In addition, the circumferential side walls 21B of the groove portion 21A are used to support the edge of the epitaxial wafer 10, and the contact area between the circumferential side walls 21B and the edge of the epitaxial wafer 10 is small, so that less impurity contamination will not be generated during the rotation process, and the back side of the epitaxial wafer 10 is exposed to reduce the back side contamination of the epitaxial wafer 10.

[0074] Further, the support portion is configured as an arc-shaped surface or an inclined surface. For example, as shown in the figure, the circumferential side wall 21B of the groove portion 21A is configured as an arc-shaped surface, which can further ensure that the contact area between the circumferential side wall 21B and the edge of the epitaxial wafer 10 is as small as possible. It is understood that the specific structure of the support portion is not limited thereto, for example, the support portion can also be configured as a supporting step structure, etc.

[0075] Furthermore, in some exemplary embodiments, Figure 7 As shown, the desorption chamber 100 further includes:

[0076] The heating platform 120 is disposed inside the desorption chamber 100 and below the first supporting platform 110;

[0077] A metal barrier layer 130 is disposed above and around the supporting surface of the first supporting platform 110;

[0078] When the first carrying platform 110 is configured as the rotating carrying platform 20 , the carrying surface of the first carrying platform 110 is arranged horizontally to drive the epitaxial wafer 10 to rotate circumferentially in a horizontal plane.

[0079] In the above scheme, the heating platform 120 in the desorption chamber 100 is mainly used to provide the temperature required for removing organic pollution, and the metal barrier 130 is mainly used to prevent the temperature loss in the chamber and play a heat preservation effect. Among them, the first carrier 110 is arranged above the heating platform 120 and is covered by the metal barrier 130. In this way, when the first carrier 110 drives the epitaxial wafer 10 to rotate circumferentially in the horizontal plane, it can ensure that each area of ​​the epitaxial wafer 10 is heated evenly.

[0080] In addition, as an exemplary embodiment, Figure 6 As shown, the structures of the first ultraviolet light chamber 200 and the second ultraviolet light chamber 300 are the same or different, and when the second carrier 210 and the third carrier 310 are configured as the rotating carrier 20, either the first ultraviolet light chamber 200 or the second ultraviolet light chamber 300 further includes:

[0081] The ultraviolet lamp 220 is disposed above the bearing surface of the rotating bearing platform 20;

[0082] The heat preservation layer 230 is disposed above the ultraviolet lamp 220;

[0083] The air inlet 240 and the air outlet 250 are respectively arranged on opposite sides of the rotating support platform 20 along the radial direction of the epitaxial wafer 10 supported thereon; wherein the supporting surface of the rotating support platform 20 is arranged horizontally to drive the epitaxial wafer 10 to rotate circumferentially in the horizontal plane.

[0084] Also, see Figure 6 As shown, any one of the first ultraviolet light chamber 200 and the second ultraviolet light chamber 300 further includes a high temperature resistant chamber side wall 260 , and the high temperature resistant chamber side wall 260 can be made of any suitable material such as high temperature resistant glass.

[0085] In the above scheme, the ultraviolet lamp 220 is mainly used for surface treatment and providing heat source; the high temperature resistant chamber side wall 260 is used to isolate the chamber from the external environment; the insulation layer 230 is used to ensure the stability of the chamber temperature. For example, the insulation layer 230 can use any suitable insulation structure such as an insulation blanket.

[0086] It should be noted that the first UV light chamber 200 is used to treat surface adsorbed ion molecules, and no gas may be introduced into the air inlet 240 and the air outlet 250; while the second UV light chamber 300 is used to grow an oxide film, and CDA gas may be introduced into the chamber through the air inlet 240 and the air outlet 250, and an oxygen-rich environment is ensured.

[0087] Also, see Figure 5As shown, the resistivity detection device for epitaxial wafers provided in the embodiment of the present disclosure may further include a prealigner 400 , a three-dimensional sample stage (XYZ Sample stage) 500 , a measurement unit, and the like.

[0088] The pre-alignment unit 400 is used to perform preliminary positioning and alignment on the epitaxial wafer 10 to ensure that the epitaxial wafer 10 can be accurately aligned with other equipment or light sources in subsequent steps.

[0089] The three-dimensional sample stage 500 is a movable platform that can accurately position the epitaxial wafer 10 in three dimensions (X, Y and Z directions). It is usually equipped with an electric drive system to achieve high-precision sample positioning to ensure that the epitaxial wafer 10 remains stable during the analysis process, facilitating high-precision measurement. The epitaxial wafer is placed on the three-dimensional sample stage 500, and the charge rods in the three-dimensional sample stage 500 will spread opposite charges on the surface of the oxide film, so that a depletion layer is formed on the surface of the epitaxial wafer under the interaction of the charges.

[0090] The measuring unit 600 is used to measure the epitaxial wafer 10 to obtain the resistivity of the epitaxial wafer 10. Specifically, the measuring unit 600 is used to measure the depletion layer to obtain the resistivity of the epitaxial wafer. In addition, the embodiment of the present disclosure also provides a resistivity detection method for an epitaxial wafer, which is applied to the resistivity detection device for an epitaxial wafer provided in the embodiment of the present disclosure, and the method includes the following steps:

[0091] Step S01, placing the epitaxial wafer 10 on the second carrier 210 of the first ultraviolet chamber 200, and preheating the epitaxial wafer 10;

[0092] Step S02, placing the epitaxial wafer 10 on the first carrier 110 of the desorption chamber 100, and performing a heating desorption process on the epitaxial wafer 10;

[0093] Step S03, placing the epitaxial wafer 10 on the third carrier 310 of the second ultraviolet chamber 300 to form an oxide film on the epitaxial wafer 10;

[0094] Step S04, placing the epitaxial wafer 10 on a sample stage, so that the oxide film forms a depletion layer under the interaction of charges;

[0095] Step S05, measuring the depletion layer to obtain the resistivity of the epitaxial wafer 10;

[0096] Among them, in the above steps, at least one of the first carrier platform 110, the second carrier platform 210 and the third carrier platform 310 is constructed as a rotating carrier platform 20, and during the corresponding processing of the epitaxial wafer 10, the epitaxial wafer 10 is driven to rotate at a uniform speed in a circumferential direction by the rotating carrier platform 20.

[0097] In the above scheme, by constructing at least one of the supporting platforms in the desorption chamber 100, the first ultraviolet light chamber 200 and the second ultraviolet light chamber 300 as a rotating supporting platform 20, the epitaxial wafer 10 is driven to rotate at a uniform speed in the circumferential direction during the pre-treatment process in the chamber, thereby reducing the risk of uneven growth of the oxide film caused by environmental factors in each chamber, thereby improving the uniformity of the oxide film required for resistivity detection of the epitaxial wafer 10, thereby improving the resistivity detection accuracy of the epitaxial wafer.

[0098] Exemplarily, before the above step S04, the method further comprises: measuring the thickness of the oxide film. Specifically, the thickness of the oxide film can be measured using an ellipsometer.

[0099] Since the principle of solving the problem by the resistivity detection method of the epitaxial wafer provided in the embodiment of the present disclosure is similar to the principle of solving the problem by the resistivity detection device of the above-mentioned epitaxial wafer, the embodiment of the resistivity detection method of the epitaxial wafer provided in the embodiment of the present disclosure can refer to the embodiment of the resistivity detection device of the above-mentioned epitaxial wafer provided in the embodiment of the present disclosure, and will not be repeated here.

[0100] There are a few points to note:

[0101] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to the general design.

[0102] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0103] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0104] The above are only specific implementations of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and the protection scope of the present disclosure shall be based on the protection scope of the claims.

Claims

1. A resistivity detection device for an epitaxial wafer, characterized in that: include: A desorption chamber, wherein a first supporting platform for supporting the epitaxial wafer is provided inside the desorption chamber; A first ultraviolet light chamber, wherein a second carrying platform for carrying the epitaxial wafer is provided inside the first ultraviolet light chamber; A second ultraviolet light chamber, wherein a third carrying platform for carrying the epitaxial wafer is provided inside the second ultraviolet light chamber; A measuring unit, used for measuring the epitaxial wafer to obtain the resistivity of the epitaxial wafer; Wherein, at least one of the first carrier platform, the second carrier platform and the third carrier platform is constructed as a rotating carrier platform, and the rotating carrier platform can carry the epitaxial wafer and drive the epitaxial wafer to rotate circumferentially.

2. The resistivity detection device for epitaxial wafer according to claim 1, characterized in that: The rotating bearing platform comprises: A susceptor for supporting epitaxial wafers; and A support frame is supported under the base, the support frame includes a rotating main shaft rotatable around its own axis, and a plurality of support arms extending radially outward and axially upward from the longitudinal axis of the rotating main shaft, the support arm includes a first end and a second end opposite to each other in the axially upward extension direction thereof, the first end supports the base, the second end is connected to the rotating main shaft, and the support arm can rotate synchronously with the rotating main shaft.

3. The resistivity detection device for epitaxial wafer according to claim 2, characterized in that: There are three support arms, and the three support arms are evenly distributed along the circumference of the rotating main shaft.

4. The resistivity detection device for epitaxial wafer according to claim 2, characterized in that: The upper surface of the base is provided with a groove portion for carrying the epitaxial wafer, and the circumferential side wall of the groove portion includes a supporting portion for supporting the edge of the epitaxial wafer.

5. The resistivity detection device for epitaxial wafer according to claim 4, characterized in that: The support portion is configured as an arc-shaped curved surface or an inclined surface.

6. The resistivity detection device for epitaxial wafer according to claim 1, characterized in that: The first carrying platform, the second carrying platform and the third carrying platform are all configured as rotating carrying platforms.

7. The resistivity detection device for epitaxial wafer according to claim 1, characterized in that: The desorption chamber also includes: A heating platform, disposed inside the desorption chamber and below the first supporting platform; A metal partition is disposed above and around the supporting surface of the first supporting platform; Wherein, when the first supporting platform is constructed as the rotating supporting platform, the supporting surface of the first supporting platform is arranged horizontally to drive the epitaxial wafer to rotate circumferentially in a horizontal plane.

8. The resistivity detection device for epitaxial wafer according to claim 1, characterized in that: The structures of the first ultraviolet light chamber and the second ultraviolet light chamber are the same or different. When the second carrier platform and the third carrier platform are configured as the rotating carrier platform, any one of the first ultraviolet light chamber and the second ultraviolet light chamber further includes: An ultraviolet lamp is arranged above the bearing surface of the rotating bearing platform; A heat-insulating layer is arranged above the ultraviolet lamp; The air inlet and the air outlet are respectively arranged on opposite sides of the rotating supporting platform along the radial direction of the epitaxial wafer carried by the rotating supporting platform; wherein the carrying surface of the rotating supporting platform is arranged horizontally to drive the epitaxial wafer to rotate circumferentially in the horizontal plane.

9. A method for detecting resistivity of an epitaxial wafer, characterized in that: The resistivity detection device for an epitaxial wafer as claimed in any one of claims 1 to 8, wherein the method comprises the following steps: Place the epitaxial wafer on the second carrier of the first ultraviolet chamber, and perform a preheating treatment on the epitaxial wafer; Carrying the epitaxial wafer on the first carrier of the desorption chamber, and performing a heating desorption process on the epitaxial wafer; placing the epitaxial wafer on a third carrier of the second ultraviolet chamber to form an oxide film on the epitaxial wafer; Placing the epitaxial wafer on a sample stage so that the oxide film forms a depletion layer under the interaction of charges; Measuring the depletion layer to obtain the resistivity of the epitaxial wafer; Among them, in the above steps, at least one of the first carrier platform, the second carrier platform and the third carrier platform is constructed as a rotating carrier platform, and during the corresponding processing of the epitaxial wafer, the epitaxial wafer is driven to rotate at a uniform speed in the circumferential direction by the rotating carrier platform.

10. The resistivity detection method of an epitaxial wafer according to claim 9, characterized in that: Before placing the epitaxial wafer on a sample stage, the method further includes: measuring the thickness of the oxide film.

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