Ion generator of ion implanter

Abstract

An ion generator related to an ion implanter is provided. The ion generator includes: an arc chamber defined by an arc chamber outer cover extending in a direction of travel; the filament is used for generating a plurality of hot electrons; the cathode is arranged at a first tail end of the arc chamber outer cover in the advancing direction and is used for generating a plurality of secondary electrons in response to bombardment of the plurality of hot electrons generated by the lamp filament; and a repulsion pole disposed at a second end of the arc chamber outer cover opposite to the first end in the advancing direction, the repulsion pole being movable relative to the arc chamber outer cover.

Description

Technical Field

[0001] The present disclosure relates to an ion generator of an implanter. Background Art

[0002] The semiconductor industry has experienced rapid growth due to continued improvements in the integration density of various electronic components, such as transistors, diodes, resistors, capacitors, etc. Generally speaking, improvements in integration density result from repeated reductions in minimum feature size, which allows more components to be integrated into a given area.

[0003] Although some integrated device manufacturers (IDMs) design and manufacture integrated circuits (ICs) themselves, fabless semiconductor companies outsource semiconductor manufacturing to semiconductor manufacturing plants or foundries. Semiconductor manufacturing consists of a series of processes, in which a device structure is manufactured by applying a series of layers to a substrate. This involves the deposition and removal of various thin film layers. The area of ​​the film to be deposited or removed is controlled by photolithography. Each of the deposition process and the removal process is usually followed by a cleaning step and an inspection step. Therefore, IDMs and foundries rely on many semiconductor equipment and semiconductor manufacturing materials that are usually provided by suppliers. There is always a need to customize or improve those semiconductor equipment and semiconductor manufacturing materials, which leads to higher flexibility, reliability and cost-effectiveness. Utility Model Content

[0004] In some embodiments, the present disclosure provides an ion generator for an ion implanter. The ion generator includes: an arc chamber, the arc chamber is defined by an arc chamber outer cover extending in a travel direction; a filament, the filament is used to generate a plurality of thermal electrons; a cathode, the cathode is disposed at a first end of the arc chamber outer cover in the travel direction and is used to generate a plurality of secondary electrons in response to the bombardment of the plurality of thermal electrons generated by the filament; and a repeller, the repeller is disposed at a second end of the arc chamber outer cover opposite to the first end in the travel direction, wherein the repeller is movable relative to the arc chamber outer cover.

[0005] In some embodiments, the present disclosure provides an ion generator for an ion implanter. The ion generator includes: an arc chamber, the arc chamber is defined by an arc chamber outer cover extending in a travel direction; a filament, the filament is used to generate a plurality of thermal electrons; a cathode, the cathode is disposed at a first end of the arc chamber outer cover in the travel direction and is used to generate a plurality of secondary electrons in response to the bombardment of the plurality of thermal electrons generated by the filament; and a repeller, the repeller is disposed at a second end of the arc chamber outer cover opposite to the first end in the travel direction, wherein the repeller is curved.

[0006] In some embodiments, the present disclosure provides an ion generator for an ion implanter. The ion generator includes: an arc chamber, the arc chamber is defined by an arc chamber outer housing extending in a travel direction; a filament, the filament is used to generate a plurality of thermal electrons; a cathode, the cathode is disposed at a first end of the arc chamber outer housing in the travel direction and is used to generate a plurality of secondary electrons in response to the bombardment of the plurality of thermal electrons generated by the filament; a repeller, the repeller is disposed at a second end of the arc chamber outer housing opposite to the first end in the travel direction, wherein the repeller is movable relative to the arc chamber outer housing and the repeller is curved; and a first drive mechanism, the first drive mechanism is coupled to the repeller and is used to move the repeller relative to the arc chamber outer housing, wherein the first drive mechanism is coupled to the repeller via a shaft attached to the repeller, and the first drive mechanism is an actuator, a track, a continuous track or a stepper motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The aspects of the present disclosure will be best understood from the following detailed description when read in conjunction with the accompanying drawings. Please note that, in accordance with standard practices in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0008] Figure 1 is a diagram illustrating an example ion generator according to some embodiments;

[0009] Figure 2 is a diagram illustrating an example arc chamber having a curved repeller 118 according to some embodiments;

[0010] Figure 3 is a diagram illustrating a side view of an example repeller according to some embodiments;

[0011] Figure 4 A diagram illustrating a front view of an example repeller according to some embodiments;

[0012] Figure 5A A diagram illustrating a side view of another example repeller at room temperature according to some embodiments;

[0013] Figure 5B For illustration according to some embodiments Figure 5A A diagram of a side view of an example repeller at elevated temperature;

[0014] Fig. 6A is a diagram illustrating an example arc chamber prior to movement of a repeller or cathode according to some embodiments;

[0015] Figure 6B is a diagram illustrating an example arc chamber after repeller or cathode movement according to some embodiments;

[0016] Figure 6Cis a diagram illustrating a side view of cathode movement according to some embodiments;

[0017] Fig.6D is a diagram illustrating a side view of both repeller movement and cathode movement according to some embodiments;

[0018] Figure 7 A flow chart illustrating a method for compensating for consumption of a cathode and a repeller according to some embodiments;

[0019] Figure 8 A diagram illustrating an exemplary control unit according to some embodiments.

[0020]

Explanation of symbols

[0021] 100:Ion Generator

[0022] 102: (ion source) arc chamber

[0023] 104: Arc chamber cover

[0024] 106: Extraction opening / extraction aperture

[0025] 108: Thermionic Emitter

[0026] 110: Filament

[0027] 111: Clip

[0028] 111': Clip

[0029] 112: cathode

[0030] 112c: Consumed part

[0031] 113: Clip

[0032] 114: Hollow area

[0033] 116: Bias power supply

[0034] 118: Rejection

[0035] 118': Rejection

[0036] 118c: Consumed part

[0037] 120: Source magnet

[0038] 122: Extraction electrode

[0039] 124: Arc chamber power supply

[0040] 126: Gas source

[0041] 130: shaft

[0042] 134: Filament power supply

[0043] 190: Control unit

[0044] 192: First driving mechanism

[0045] 194: Second driving mechanism

[0046] 202: Overall plasma region

[0047] 206: Ion

[0048] 212: Boundary

[0049] 214: Boundary

[0050] 302: front surface

[0051] 304: Rear surface

[0052] 306: Round belt

[0053] 512: First metal layer

[0054] 514: Second metal layer

[0055] 602: Distance sensor

[0056] 604: Distance sensor

[0057] 700: Method

[0058] 702: Operation

[0059] 704: Operation

[0060] 706: Operation

[0061] 874: Processor

[0062] 876:Memory

[0063] 878: Machine Learning (ML) Module

[0064] 880: Communication components

[0065] 882: Data storage device

[0066] B: Magnetic field in the X direction

[0067] D1: Displacement

[0068] D2: Second displacement

[0069] D3: The third displacement

[0070] M1: Mobile

[0071] M2: Mobile DETAILED DESCRIPTION

[0072] The following disclosure provides many different embodiments or examples for implementing the different features of the provided subject matter. Specific examples of components and configurations will be described below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting. For example, a first feature formed above or on a second feature in the subsequent description may include an embodiment in which the first feature and the second feature are formed in direct contact, and may also include an embodiment in which an additional feature may be formed between the first feature and the second feature so that the first feature and the second feature are not in direct contact. In addition, the present disclosure may repeat reference numbers and / or letters in various examples. This repetition is for the purpose of simplicity and clarity and does not itself dictate the relationship between the various embodiments and / or configurations discussed.

[0073] Additionally, to facilitate description of the relationship of one element or feature to another element or feature as illustrated in the figures, spatially relative terms, such as "below," "beneath," "lower," "above," "upper," and the like, may be used herein. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be similarly interpreted accordingly.

[0074] Additionally, source / drain regions may refer to source or drain individually or collectively depending on the context. For example, a device may include a first source / drain region and a second source / drain region, among other components. The first source / drain region may be a source region and the second source / drain region may be a drain region, or vice versa. Those of ordinary skill in the art may recognize many variations, modifications, and alternatives.

[0075] Some embodiments of the disclosure are described. Additional operations may be provided before, during, and / or after the stages described in these embodiments. Some of the stages described may be replaced or eliminated for different embodiments. Some of the features described below may be replaced or eliminated and additional features may be added for different embodiments. Although some embodiments are discussed with respect to operations performed in a particular order, these operations may be performed in another logical order.

[0076] Ion implantation is a low temperature process by which ions of an element are accelerated into a solid target, thereby changing the physical, chemical or electrical properties of the target. Ion implantation is widely used in semiconductor device manufacturing. Semiconductor doping with boron, phosphorus or arsenic is a common application of ion implantation. When implanted in a semiconductor, each dopant atom can generate charge carriers in the semiconductor after annealing. For p-type dopants, holes can be generated, while for n-type dopants, electrons can be generated. This changes the conductivity near the semiconductor. In addition, ion implantation is used to prepare silicon on insulator (SOI) substrates from conventional bulk silicon substrates. In the separation by implantation of oxygen (SIMOX) process, buried high-dose oxygen implants are converted into silicon oxide by a high-temperature annealing process.

[0077] An ion implanter typically includes an ion generator for generating an ion beam, ion beam transport optics for accelerating the ion beam, and a process chamber in which ion implantation on a semiconductor wafer occurs. The ions are typically positively charged. During ion implantation, the charged ion beam strikes a semiconductor wafer in the process chamber, thereby producing a doped semiconductor wafer as the dopant ions diffuse into the wafer.

[0078] The repeller (sometimes also referred to as the "counter cathode") is usually coupled to the outer cover of the ion source arc chamber (sometimes also referred to as the "arc chamber"). The repeller is used in conjunction with the filament to "repel" the electrons generated from the cathode, so that the electrons generated from the cathode travel back and forth in the arc chamber in a direction perpendicular to the travel direction of the cathode. Therefore, due to the increase in travel distance, the electrons have an increased chance of colliding with molecules of the gas introduced into the arc chamber. Therefore, due to more collisions, more ions are generated in the arc chamber.

[0079] However, once all components of the ion generator are assembled, the geometry of the arc chamber is fixed. After a period of use, the consumption of the filament, cathode, and repeller may cause the geometry of the arc chamber to change. For example, due to the consumption of the cathode and repeller, the distance between the cathode and repeller in the direction of travel may increase. Therefore, the optimal position or shape of the plasma generated in the arc chamber may drift or change. In order to compensate for this drift or change, a larger drive current, a higher bias voltage, and an increased gas flow rate are used.

[0080] According to some aspects of the disclosure, an ion generator for an ion implanter is provided. The ion generator includes: an arc chamber, the arc chamber being defined by an arc chamber outer cover extending in a travel direction; a filament, the filament being used to generate a plurality of hot electrons; a cathode, the cathode being disposed at a first end of the arc chamber outer cover in the travel direction and being used to generate a plurality of secondary electrons in response to the bombardment of the hot electrons generated by the filament; and a repeller, the repeller being disposed at a second end of the arc chamber outer cover opposite to the first end in the travel direction. The repeller can be moved relative to the arc chamber outer cover. The movement of the repeller can compensate for the drift or change of the optimal position or shape of the plasma generated in the arc chamber caused by the consumption of the cathode and the repeller. Therefore, the aging effect is minimized, the maintenance count is reduced, the life of the components of the ion generator 100 is extended, and the use of expensive or toxic reactant gases is reduced.

[0081] In some embodiments, the repeller is curved rather than flat. In one example, the repeller includes: a front surface, the front surface facing the cathode; and a rear surface, the rear surface opposite the front surface. The front surface is a concave surface when viewed from the cathode, and the rear surface is a convex surface when viewed toward the cathode. Therefore, the travel path and travel time of the secondary electrons are increased, thereby increasing the number of collisions. The overall plasma region is expanded in a plane perpendicular to the travel direction. The plasma density and ion density are also increased.

[0082] Example Ion Generator

[0083] Figure 1 FIG. 1 is a diagram illustrating an example ion generator according to some embodiments. The ion generator 100 may be used in an ion implanter, such as an inductively heated cathode (IHC) ion generator used in a high current ion implantation apparatus.

[0084] exist Figure 1 In the example shown, according to some embodiments, the ion generator 100 includes an (ion source) arc chamber 102. In addition, the arc chamber 102 has an arc chamber outer cover 104 and an extraction opening 106 at a side of the arc chamber outer cover 104. The extraction opening 106 is used to extract or discharge ions and / or other impurities generated in the arc chamber 102. The arc chamber outer cover 104 can be made of a conductive material with a high melting point, so the arc chamber outer cover 104 can be used under high temperature conditions. The materials used to form the arc chamber outer cover 104 may include, but are not limited to, tungsten (W), molybdenum (Mo) and tantalum (Ta), alloys thereof, or graphite (C), although other conductive materials may be used to form the arc chamber outer cover 104 in addition or alternatively.

[0085] The thermal electron emitter 108 is disposed in a first horizontal direction (ie, Figure 1The arc chamber 102 is coupled to one side of the arc chamber outer cover 104 in the X direction as shown in FIG. Figure 1 In some embodiments, the thermionic electron emitter 108 includes a filament 110 and a cathode 112 .

[0086] exist Figure 1 In the example shown, cathode 112 protrudes from arc chamber outer cover 104 into arc chamber 102, so one end of the cathode is located in arc chamber 102 and the other end of the cathode is located outside arc chamber 102. In some embodiments, clips 113 are clamped to both sides of cathode 112 to improve the stability of cathode 112.

[0087] exist Figure 1 In the example shown, the filament 110 is located in the hollow area 114 of the cathode 112, but is not in physical contact with the cathode 112. In some embodiments, the clips 111 and 111' are clamped on the two ends of the filament 110 extending outside the cathode 112 to improve the stability of the filament 110. The filament power supply 134 is electrically connected to the clips 111 and 111' to provide power to the filament 110.

[0088] The filament 110 is used to generate thermal electrons. More specifically, the filament 110 is powered by the filament power supply 134 and the current passing through the filament 110 heats the filament 110 to generate thermal electrons. When the filament 110 is heated to the thermionic emission temperature by the filament power supply 134, the thermal electrons generated by the filament 110 are emitted.

[0089] A bias power supply 116 is used to bias the cathode 112 so that hot electrons emitted by the filament 110 can be accelerated toward the cathode 112. When these hot electrons strike the cathode 112, the cathode 112 will emit secondary electrons into the arc chamber 102. In some embodiments, the cathode 112 is also heated to a thermionic emission temperature, and in addition to the secondary electrons, hot electrons are also emitted from the cathode 112. Unless explicitly stated, secondary electrons are discussed throughout this disclosure as primary electrons emitted by the cathode 112, but it should be understood by those of ordinary skill in the art that additional hot electrons emitted by the cathode 112 are also present and contribute to the generation of plasma and ions.

[0090] In addition, an arc chamber power supply 124 is electrically connected to the arc chamber outer housing 104. The arc chamber power supply 124 is used to bias the arc chamber outer housing 104 relative to the cathode 112, so that secondary electrons emitted by the cathode 112 (and in some embodiments where the cathode 112 is also heated, thermal electrons) are accelerated in the arc chamber 102. Therefore, the secondary electrons emitted by the cathode 112 acquire high kinetic energy, and plasma is formed in the arc chamber 102 due to collisions between the secondary electrons and molecules of the reactant gas introduced into the arc chamber 102.

[0091] A repeller 118 (or counter cathode) is coupled to the arc chamber outer cover 104. A shaft 130 is attached to the repeller 118. Figure 1 In the example shown, the thermal electron emitter 108 is positioned on one side of the arc chamber outer housing 104 in the X direction, and the repeller 118 is positioned on the opposite side of the arc chamber outer housing 104 in the X direction. In addition, the repeller 118 at the other end of the arc chamber outer housing 104 can be biased at the same or similar potential as the cathode 112 to repel high-energy thermal electrons in the arc chamber 102. The material used to form the repeller 118 may include, but is not limited to, tungsten, although other conductive materials may be used to form the repeller 118 in addition or alternatively. As discussed above, the repeller 118 repels secondary electrons in the X direction and increases the travel time of the secondary electrons. Therefore, additional ionization collisions may be achieved.

[0092] As will be referenced below Figure 2 , Figure 3 , Figure 4 , Figure 5A and Figure 5B Discussed in more detail, the repeller 118 is not flat. In some embodiments, the repeller 118 has a curved front surface facing the cathode 112. In one example, the repeller 118 has a "bowl shape". As will be discussed below, the spherical cap shape of the repeller 118 can increase the plasma density and therefore the ion density in the arc chamber 102.

[0093] exist Figure 1 In the example shown, the source magnet 120 is disposed outside the arc chamber 102. The source magnet 120 is used to generate a magnetic field within the arc chamber 102 and thus to confine the hot electrons formed in the arc chamber 102. Figure 1 Two source magnets 120 are illustrated in FIG. 1 , but in other embodiments, one or more than two source magnets 120 may be used to generate the magnetic field.

[0094] exist Figure 1 In the example shown, a magnetic field in the X direction is formed. Figure 1 Therefore, the secondary electrons formed in the arc chamber 102 follow the Figure 1 Specifically, the secondary electrons move in a plane perpendicular to the magnetic field (i.e., Figure 1 The YZ plane shown in FIG. 1 moves in a circle and in the direction of the magnetic field (i.e., Figure 1 The spiral path increases the travel length and travel time of the secondary electrons, thereby increasing the number of ionization collisions.

[0095] exist Figure 1In the example shown, a gas source 126 is coupled to the arc chamber outer cover 104. The gas source 126 is used to introduce gas into the arc chamber 102. In some embodiments, the gas source 126 includes one or more gas bottles or gas reservoirs. In some other embodiments, the gas source 126 includes an oven that heats a substance to produce the desired gas. In some embodiments, the gas source 126 is used to apply a reactant gas and a diluent gas (e.g., hydrogen) to the arc chamber 102. In some examples, the reactant gas is a dopant gas, such as one of the following: carbon dioxide (CO 2 ), carbon monoxide (CO), germanium tetrafluoride (GeF 4 ), Boron trifluoride (BF 3 ), Boron difluoride (BF 2 ), oxygen (O 2 ), phosphine (PH 3 ), ammonia (NH 3 ) and arsenic (AsH 3 ). Of these exemplary types of reactant gases, germanium tetrafluoride and boron trifluoride are relatively expensive, while phosphine and arsine are highly toxic. Therefore, it would be beneficial to reduce the use of these reactant gases.

[0096] The reactant gas and the diluent gas may be introduced into the arc chamber 102 through the same conduit. That is, the reactant gas and the diluent gas are premixed in the conduit before entering the arc chamber 102. Alternatively, the reactant gas and the diluent gas may be introduced into the arc chamber 102 through different conduits. That is, the reactant gas and the diluent gas are mixed in the arc chamber 102.

[0097] Ions 206 of the reactant gas are thus generated in the arc chamber 102. Figure 1 In the example shown, the extraction electrode 122 is located outside the arc chamber 102 in front of the extraction opening 106. The extraction electrode 122 is used to extract ions 206 from the plasma formed in the arc chamber 102. More specifically, ions 206 of the reactant gas are extracted from the arc chamber 102 through the extraction aperture 106 by the extraction electrode 122. These ions 206 are then guided and accelerated by the implanter for ion implantation on the semiconductor wafer.

[0098] The control unit 190 is electrically connected to various components of the ion generator 100, including but not limited to the filament power supply 134, the bias power supply 116, the arc chamber power supply 124, the gas source 126, the first drive mechanism 192, and the second drive mechanism 194. The control unit 190 is used to control the operation of the ion generator 100 by adjusting various operating parameters of the ion generator. The details of the control unit 190 will be discussed below.

[0099] The first drive mechanism 192 is used to drive the repeller 118 via, for example, the shaft 130, so that the repeller 118 can move in the X direction (i.e., the travel direction) relative to the arc chamber outer housing 104. The second drive mechanism 194 is used to drive the cathode 112 (and the filament 110, in some embodiments), so that the cathode 112 can move in the X direction (i.e., the travel direction) relative to the arc chamber outer housing 104. The first drive mechanism 192 and the second drive mechanism 194 are controlled by the control unit 190. As will be discussed in more detail below, due to the consumption of the cathode 112 and the repeller 118, the movement of at least one of the repeller 118 and the cathode 112 can compensate for the drift or change in the optimal position or shape of the plasma generated in the arc chamber 102. Therefore, the aging effects are minimized, the maintenance count is reduced, the life of the components of the ion generator 100 is extended, and the use of expensive or toxic reactant gases is reduced.

[0100] Example of curved repeller and its operation

[0101] Figure 2 FIG. 1 is a diagram illustrating an example arc chamber 102 having a repeller 118 that is curved, in accordance with some embodiments. Figure 3 is a diagram illustrating a side view of an example repeller 118 according to some embodiments. Figure 4 is a diagram illustrating a front view of an example repeller 118 according to some embodiments.

[0102] exist Figure 2 In the example shown, an overall plasma region 202 is formed in the arc chamber 102. The overall plasma region 202 is quasi-neutral (i.e., the density of electrons and the density of ions are substantially the same). The overall plasma region 202 has a boundary 212. The overall plasma region 202 extends between the cathode 112 and the repeller 118 in the X direction.

[0103] Compared to a flat conventional repeller, the overall plasma region 202 is larger in the YZ plane than the paired overall plasma region with the boundary 214. The repeller 118 is curved. Therefore, the electric field generated by the repeller 118 has both a first component in the X direction and a second component perpendicular to the X direction. The second component generates a force that confines the secondary electrons in the YZ plane. Fewer secondary electrons strike the inner surface of the arc chamber outer cover 104 in a given time period. Therefore, the travel path and travel time of the secondary electrons increase, thereby increasing the number of collisions. The overall plasma region 202 expands in the YZ. The plasma density and ion density also increase.

[0104] exist Figure 3 and Figure 4In the example shown, the repeller 118 has a front surface 302 and a rear surface 304. When viewed from the front (i.e., from the cathode 112), the front surface 302 is a concave surface. When viewed from the back (i.e., toward the cathode 112), the rear surface 304 is a convex surface. When viewed from the front, the repeller 118 also has a rounded band 306. In some embodiments, the front surface 302 is the surface of a first spherical cap, and the rear surface 304 is the surface of a second spherical cap, and the radius of the second spherical cap is greater than the radius of the first spherical cap. Therefore, the repeller 118 has a "bowl shape."

[0105] It should be understood that the front surface 302 and the rear surface 304 do not need to be spherical cap surfaces, and other curved surfaces may be used in other embodiments. In some embodiments, the repeller 118 may have a conical shape, a dish shape, or other suitable shapes.

[0106] Figure 5A FIG. 4 is a diagram illustrating a side view of another example repeller 118 ′ at room temperature according to some embodiments. Figure 5B For illustration according to some embodiments Figure 5A A diagram of a side view of an example repeller 118' at a higher temperature is shown.

[0107] exist FIG. 5A to FIG. 5B In the example shown, the repeller 118' does not have to bend at room temperature. The repeller 118' has two metal layers, namely a first metal layer 512 and a second metal layer 514 coupled to each other. At room temperature, the repeller is substantially flat. However, the first metal layer 512 is made of a first metal having a first coefficient of thermal expansion (CTE), and the second metal layer 514 is made of a second metal having a second CTE different from the first CTE. When the temperature rises to an elevated temperature exceeding room temperature (e.g., due to operation of the arc chamber 102 or due to purposeful heating of the repeller 118'), the repeller 118' flexes and becomes curved due to the difference between the first CTE and the second CTE. In one embodiment, the elevated temperature is between 1000 degrees Celsius and 2000 degrees Celsius. In another embodiment, the elevated temperature is between 1200 degrees Celsius and 1800 degrees Celsius. In yet another embodiment, the elevated temperature is between 1400 degrees Celsius and 1600 degrees Celsius. In another embodiment, the elevated temperature is about 1500 degrees Celsius.

[0108] In one embodiment, the first metal is tungsten (W) and the second metal is molybdenum (Mo). In another embodiment, the first metal is molybdenum (Mo) and the second metal is tungsten (W). In other embodiments, the first metal and the second metal may be two of the following: niobium, molybdenum, tantalum, tungsten, rhenium, and alloys.

[0109] Movement of repeller and cathode

[0110] Fig. 6A FIG. 1 is a diagram illustrating an example arc chamber 102 before the repeller or cathode is moved, according to some embodiments. According to some embodiments, Figure 6B FIG. 1 is a diagram illustrating an example arc chamber 102 after the repeller or cathode has been moved. According to some embodiments, Figure 6C is a diagram illustrating a side view of cathode movement. According to some embodiments, Fig.6D It is a diagram showing a side view of both the repeller movement and the cathode movement.

[0111] exist Fig. 6A In the example shown, after the ion generator 100 has been operated for a certain period of time (e.g., 1 hour, 10 hours, 100 hours, etc.), the cathode 112 and the repeller 118 have been consumed. Fig. 6A In the example shown, the consumed portion 112c of the cathode 112 has been consumed, and the consumed portion 118c of the repeller 118 has been consumed. Therefore, the cathode 112 and the repeller 118 are spaced apart in the direction of travel (ie, Fig. 6A As a result, the distance in the X direction (shown in FIG. 1 ) increases. Therefore, the optimal position or shape of the plasma generated in the arc chamber 102 drifts or changes. There is a gap between the boundary 212 of the overall plasma region 202 and the cathode 112; there is a gap between the boundary 212 of the overall plasma region 202 and the repeller 118.

[0112] The consumption depth of the cathode 112 is the depth of the consumption portion 112c in the traveling direction; the consumption depth of the repellent 118 is the depth of the consumption portion 118c in the traveling direction. Fig. 6A In the example shown, the distance sensor 602 is attached to the arc chamber outer housing 104 near the cathode 112, and the distance sensor 604 is attached to the arc chamber outer housing 104 near the repeller 118. The distance sensor 602 measures the consumption depth of the cathode 112; the distance sensor 604 measures the consumption depth of the repeller 118. In one implementation, the consumption depth of the cathode 112 or the repeller 118 is measured by calculating the change in the distance between the distance sensor 602 and the cathode 112 or between the distance sensor 604 and the repeller 118. Specifically, a first distance between the distance sensor 604 and the repeller 118 is measured at a first moment, and a second distance between the distance sensor 604 and the repeller 118 is measured at a second moment after the first moment, and then the difference between the first distance and the second distance is calculated.

[0113] In one embodiment, distance sensors 602 and 604 are ultrasonic distance sensors (sometimes also referred to as "sonar sensors"). High frequency sound waves are emitted toward cathode 112 or repeller 118, and the reflected waves are picked up by the receiver of the ultrasonic distance sensor. In another embodiment, distance sensors 602 and 604 are infrared (IR) distance sensors. The distance is measured based on the angle of the reflected IR beam. In another embodiment, distance sensors 602 and 604 are laser distance sensors. The distance is measured by using the constant speed of light in air and the time between emitting and receiving the laser. In one example, the laser distance sensor is a Light Detection and Ranging (LiDAR) sensor.

[0114] exist Figure 6B In the example shown, the repelling electrode 118 is in the direction of travel (ie, Figure 6B The displacement D1 is moved in the X direction (shown in FIG. 1 ) toward the cathode 112. The movement Figure 6B The displacement D1 is represented as "M1". Fig. 6A 1. The displacement is a function of the depth of the consumed portion 112c and the depth of the consumed portion 118c in the direction of travel shown. In one example, the displacement is the sum of the depth of the consumed portion 112c and the depth of the consumed portion 118c. By compensating for the consumption of the cathode 112 and the repeller 118, an optimal position or shape of the plasma generated in the arc chamber 102 can be maintained.

[0115] exist Figure 6B In the example shown, the displacement D1 of the repeller 118 is achieved by moving a shaft 130 attached to the repeller 118. The shaft 130 is formed by Figure 1 The first driving mechanism 192 shown in FIG. 1 moves. The first driving mechanism 192 is composed of Figure 1 The first drive mechanism 192 is controlled by the control unit 190 shown. In one implementation, the first drive mechanism 192 is an actuator, a track, a continuous track, a stepper motor, a gear, a belt, or a combination thereof. It should be understood that this is not intended to be limiting, and other implementations of the first drive mechanism 192 are within the scope of the disclosure. When the first drive mechanism 192 receives an instruction from the control unit 190 to move the calculated displacement, the first drive mechanism 192 drives the shaft 130 to the calculated displacement.

[0116] Despite Figure 6B In the example shown, the displacement is shown as a displacement in the X direction, but it should be understood that when the consumption of the repeller 118 or the cathode 112 is not even in the XY plane for some reason, the displacement may be in the X direction and in the YZ plane. In other words, in other embodiments, the displacement or movement of the repeller 118 may be a three-dimensional displacement or movement.

[0117] exist Figure 6C In the example shown, the cathode 112 moves in place of the repelling electrode 118. Specifically, the cathode 112 moves in the direction of travel (ie, Figure 6C The displacement D1 is moved in the X direction (shown in FIG. 1 ) toward the repelling electrode 118. The movement Figure 6C Similarly, the displacement D1 is Fig. 6A 1. The displacement is a function of the depth of the consumed portion 112c and the depth of the consumed portion 118c in the direction of travel shown. In one example, the displacement is the sum of the depth of the consumed portion 112c and the depth of the consumed portion 118c. By compensating for the consumption of the cathode 112 and the repeller 118, an optimal position or shape of the plasma generated in the arc chamber 102 can be maintained.

[0118] exist Figure 6C In the example shown, the displacement D1 of the cathode 112 is achieved by moving, for example, a shaft attached to the repeller 118. Figure 1 The second driving mechanism 194 shown in FIG. 1 moves, and the second driving mechanism 194 is Figure 1 The control unit 190 shown is controlled. In one implementation, the second drive mechanism 194 is an actuator, a track, a continuous track, a stepper motor, a gear, a belt, or a combination thereof. It should be understood that this is not intended to be limiting, and other implementations of the second drive mechanism 194 are within the scope of the disclosure. When the second drive mechanism 194 receives an instruction to move the calculated displacement from the control unit 190, the second drive mechanism 194 drives the calculated displacement by the shaft attached to the repeller 118.

[0119] Despite Figure 6C In the example shown, the displacement is shown as displacement in the X direction, but it should be understood that when the consumption of the repeller 118 or the cathode 112 is not even in the XY plane for some reason, the displacement may be in the X direction and in the YZ plane. In other words, in other embodiments, the displacement or movement of the cathode 112 may be a three-dimensional displacement or movement.

[0120] exist Fig.6D In the example shown, both the repeller 118 and the cathode 112 move. Specifically, the repeller 118 moves in the direction of travel (ie, Fig.6D The movement is made by a third displacement D3 in the X direction (shown in FIG. 1 ) toward the cathode 112. Fig.6D The cathode 112 is in the traveling direction (ie, Fig.6D The movement is a second displacement D2 in the X direction (shown in FIG. 1 ) toward the repelling electrode 118. Fig.6D The sum of the second displacement D2 and the third displacement D3 is equal to the displacement D1. Similarly, the sum of the second displacement D2 and the third displacement D3 is Fig. 6A1. The depth of the consumed portion 112c and the depth of the consumed portion 118c in the direction of travel are shown. In one example, the sum of the second displacement D2 and the third displacement D3 is the sum of the depth of the consumed portion 112c and the depth of the consumed portion 118c. By compensating for the consumption of the cathode 112 and the repeller 118, an optimal position or shape of the plasma generated in the arc chamber 102 can be maintained.

[0121] exist Fig.6D In the example shown, the second displacement D2 of the cathode 112 is achieved by moving, for example, a shaft attached to the repeller 118. Figure 1 The second drive mechanism 194 shown in FIG. 1 moves, and the second drive mechanism 194 is composed of Figure 1 On the other hand, the third displacement D3 of the repelling electrode 118 is achieved by moving the shaft 130 attached to the repelling electrode 118. The shaft 130 is controlled by Figure 1 The first driving mechanism 192 shown in FIG. 1 moves. The first driving mechanism 192 is composed of Figure 1 The control unit 190 shown controls.

[0122] Figure 7 FIG. 7 is a flow chart illustrating a method 700 for compensating for consumption of a cathode and a repeller according to some embodiments. Figure 7 In the example shown, method 700 includes operations 702, 704, and 706. Additional operations may be performed.

[0123] In operation 702, the consumption depth of the cathode 112 and the consumption depth of the repeller 118 are measured. The consumption depth of the cathode 112 is Fig. 6A The consumption depth of the consumption portion 112c shown in the travel direction; the consumption depth of the repelling electrode 118 is Fig. 6A The depth of the consumption portion 118c shown in the direction of travel. In one implementation, by Fig. 6A The distance sensor 602 fixed on the arc chamber cover 104 is used to measure the consumption depth of the cathode 112; Fig. 6A A distance sensor 604 is shown mounted on the arc chamber housing 104 to measure the consumption depth of the repeller 118 .

[0124] At operation 704, at least one of a displacement of the cathode 112 and a displacement of the repeller 118 is calculated or determined based on the consumption depth of the cathode 112 and the consumption depth of the repeller 118. Figure 6B In one embodiment shown, only the repeller 118 moves. Therefore, only the displacement of the repeller 118 is calculated. Figure 6C In another embodiment shown, only the cathode 112 moves. Therefore, only the displacement of the cathode 112 is calculated. Figure 6CIn yet another embodiment shown, both the cathode 112 and the repeller 118 move. Thus, both the displacement of the cathode 112 and the displacement of the repeller 118 are calculated.

[0125] At operation 706, at least one of the cathode 112 and the repeller 118 is moved according to the calculated displacement at operation 704. Figure 6B In the embodiment shown, only the repeller 118 is moved according to the displacement of the repeller 118. Figure 6C In another embodiment shown, only the cathode 112 is moved according to the displacement of the cathode 112. Figure 6C In yet another embodiment shown, both the cathode 112 and the repeller 118 are moved according to the displacement of the cathode 112 and the displacement of the repeller 118, respectively.

[0126] Control unit and machine learning

[0127] According to some embodiments, Figure 8 FIG. 1 is a diagram illustrating an example control unit 190. As discussed above, the control unit 190 and Figure 1 The various components of the ion generator 100 shown are in electrical communication, including the filament power supply 134, the bias power supply 116, the arc chamber power supply 124, the gas source 126, the first drive mechanism 192, and the second drive mechanism 194. The control unit 190 is further connected to Fig. 6A Distance sensors 602 and 604 are shown in electrical communication. It should be understood that control unit 190 may be in electrical communication with other components of ion generator 100 as desired.

[0128] exist Figure 8 In the example shown, the control unit 190 also includes, among other components, a processor 874, a memory 876, a machine learning (ML) module 878, a communication component 880, and a data storage device 882. The control unit 190 is generally configured to receive signals from other components of the ion generator 100, process a plurality of signals, calculate real-time adjustments to operating parameters or characteristics, convert the real-time adjustments into adjustment signals, and transmit a plurality of adjustment signals to other components of the ion generator 100.

[0129] The processor 874 is used to process and analyze signals and execute instructions stored in the memory. In some embodiments, the processor 874 is a central processing unit (CPU), a multi-core processor, a distributed processing system, an application specific integrated circuit (ASIC) and / or a suitable processing unit.

[0130] The memory 876 is used to store temporary variables or other intermediate information during signal processing performed by the processor 874. In some embodiments, the memory 876 is a random-access memory (RAM), such as a static random-access memory (SRAM).

[0131] The data storage device 882 is used to store any information related to the operation of the ion generator 100, such as the above-referenced Fig. 6A The consumption depth of cathode 112 and the consumption depth of repeller 118 are discussed. In some embodiments, data storage device 882 is an electronic, magnetic, optical, electromagnetic, infrared and / or semiconductor system (or device or apparatus). For example, data storage device 882 includes semiconductor or solid-state memory, magnetic tape, removable computer disk, random-access memory (RAM), read-only memory (ROM), hard disk and / or optical disk. In some embodiments using optical disks, data storage device 882 includes compact disk-read only memory (CD-ROM), compact disk-read / write (CD-R / W) and / or digital video disc (DVD).

[0132] Communications component 880 allows software and data to be transferred between control unit 190 and external components such as Fig. 6A The distance sensors 602 and 604 are shown. Figure 1 The first driving mechanism 192 and Figure 1 The communication component 880 may include a modem, a network interface (such as an Ethernet card), a communication port, or the like. The software and data transmitted via the communication component 880 are in the form of signals, which may be electronic signals, electromagnetic signals, optical signals, or other signals that can be received by the communication component. These signals are provided to the communication component 880 via a communication path, which may be implemented using wires or cables, optical fibers, telephone lines, cellular telephone links, RF links, or other communication channels.

[0133] The machine learning (ML) module 878 has a machine learning algorithm for establishing and improving an operating model with respect to at least one operating parameter and / or a relationship between or among multiple operating parameters. The operating model can be trained by the machine learning module 878 based on prior data about a certain type of arc chamber 102 generated from previous operations in combination with the operating parameters of the cathode 112 and the repeller 118. Such prior data can be stored externally and accessible to the machine learning module 878 via the communication component 880. Alternatively, such prior data can be stored internally in a data storage device 882. Data sets (e.g., training data sets, test data sets, etc.) are therefore accessible to the machine learning module 878 for training and testing.

[0134] Conventionally, operating parameters such as the power (or voltage, or current) provided to the filament 110, the bias voltage applied to the cathode 112, the bias voltage applied to the arc chamber outer cover 104, and the flow rate of the gas source 126 are used to tune to achieve an optimal position or shape of the plasma generated in the arc chamber 102. However, according to the embodiments disclosed herein, operating parameters such as the consumption depth of the cathode 112, the consumption depth of the repeller 118, the displacement of the cathode 112, the displacement of the repeller 118, the shape of the repeller 118 (e.g., Figure 3 Additional operating parameters such as the curvature of the front surface 302 shown can be used for tuning. Therefore, due to the multiple additional operating parameters, tuning becomes faster and more accurate and a greater tuning tolerance can be achieved.

[0135] The pre-established operating model generated by the machine learning module 878 can be used as a standard or reference for the processor 874 to perform the following processes: (i) determine the recommended combination of operating parameters; (ii) determine the deviation between the current value of the operating parameter and the recommended value; (iii) generate an immediate adjustment signal, and the plurality of immediate adjustment signals will be generated by the corresponding components (e.g., Figure 1 Thus, during the operation of the ion generator 100, if real-time adjustment is required, the control unit 190 will instantly transmit the real-time adjustment signal to the corresponding components via the communication component 880.

[0136] According to some aspects of the disclosure, an ion generator for an ion implanter is provided. The ion generator includes: an arc chamber, the arc chamber being defined by an arc chamber outer housing extending in a travel direction; a filament, the filament being used to generate a plurality of thermal electrons; a cathode, the cathode being disposed at a first end of the arc chamber outer housing in the travel direction and being used to generate a plurality of secondary electrons in response to the bombardment of the plurality of thermal electrons generated by the filament; and a repeller, the repeller being disposed at a second end of the arc chamber outer housing opposite to the first end in the travel direction, wherein the repeller is movable relative to the arc chamber outer housing. In some embodiments, the ion generator further includes a first drive mechanism, the first drive mechanism being coupled to the repeller and being used to move the repeller relative to the arc chamber outer housing. In some embodiments, the first drive mechanism is coupled to the repeller via a shaft attached to the repeller. In some embodiments, the first drive mechanism is one of the following: an actuator, a track, a continuous track, and a stepper motor. In some embodiments, the ion generator further includes a first distance sensor, which is attached to the arc chamber outer cover and is used to measure a consumption depth of the repeller in the travel direction. In some embodiments, the consumption depth of the repeller is measured by the following steps: measuring a first distance between the first distance sensor and the repeller at a first moment; measuring a second distance between the first distance sensor and the repeller at a second moment after the first moment; and calculating a difference between the first distance and the second distance. In some embodiments, a displacement of the repeller is determined based on the consumption depth of the repeller. In some embodiments, the ion generator further includes a second drive mechanism, which is coupled to the cathode and is used to move the cathode relative to the arc chamber outer cover. In some embodiments, the ion generator further includes a second distance sensor, which is attached to the arc chamber outer cover and is used to measure a consumption depth of the cathode in the travel direction. In some embodiments, the consumption depth of the cathode is measured by the following steps: measuring a first distance between the second distance sensor and the cathode at a first moment; measuring a second distance between the first distance sensor and the repeller at a second moment after the first moment; and calculating a difference between the first distance and the second distance. In some embodiments, a displacement of the cathode is determined based on the consumption depth of the cathode. In some embodiments, the displacement of the cathode is zero, and the displacement of the repeller is the sum of the consumption depth of the repeller and the consumption depth of the cathode. In some embodiments, the displacement of the repeller is zero, and the displacement of the cathode is the sum of the consumption depth of the repeller and the consumption depth of the cathode. In some embodiments, the sum of the displacement of the cathode and the displacement of the repeller is equal to the sum of the consumption depth of the repeller and the consumption depth of the cathode. In some embodiments, the repeller is curved.

[0137] According to some aspects of the disclosed content, an ion generator for an ion implanter is provided. The ion generator includes: an arc chamber, the arc chamber is defined by an arc chamber outer cover extending in a travel direction; a filament, the filament is used to generate a plurality of thermal electrons; a cathode, the cathode is disposed at a first end of the arc chamber outer cover in the travel direction and is used to generate a plurality of secondary electrons in response to the bombardment of the plurality of thermal electrons generated by the filament; and a repeller, the repeller is disposed at a second end of the arc chamber outer cover opposite to the first end in the travel direction, wherein the repeller is curved. In some embodiments, the repeller includes: a front surface, the front surface faces the cathode; and a rear surface, the rear surface is opposite to the front surface; and wherein the front surface is a concave surface when viewed from the cathode, and the rear surface is a convex surface when viewed toward the cathode. In some embodiments, the ion generator further includes a first drive mechanism, the first drive mechanism is coupled to the repeller and is used to move the repeller relative to the arc chamber outer cover.

[0138] According to some aspects of the disclosure, a method for operating an ion generator of an ion implanter is provided. The method includes: measuring a consumption depth of a cathode and a consumption depth of a repeller; determining at least one of a displacement of the repeller and a displacement of the cathode based on the consumption depth of the cathode and the consumption depth of the repeller; and moving at least one of the cathode and the repeller according to at least one of the displacement of the repeller and the displacement of the cathode. In some embodiments, the displacement of the cathode is zero, and the displacement of the repeller is a sum of the consumption depth of the cathode and the consumption depth of the repeller.

[0139] In some embodiments, the present disclosure provides an ion generator for an ion implanter. The ion generator includes: an arc chamber, the arc chamber is defined by an arc chamber outer housing extending in a travel direction; a filament, the filament is used to generate a plurality of thermal electrons; a cathode, the cathode is disposed at a first end of the arc chamber outer housing in the travel direction and is used to generate a plurality of secondary electrons in response to the bombardment of the plurality of thermal electrons generated by the filament; a repeller, the repeller is disposed at a second end of the arc chamber outer housing opposite to the first end in the travel direction, wherein the repeller is movable relative to the arc chamber outer housing and the repeller is curved; and a first drive mechanism, the first drive mechanism is coupled to the repeller and is used to move the repeller relative to the arc chamber outer housing, wherein the first drive mechanism is coupled to the repeller via a shaft attached to the repeller, and the first drive mechanism is an actuator, a track, a continuous track or a stepper motor. In some embodiments, the ion generator further includes: a second driving mechanism, which is coupled to the cathode and used to move the cathode relative to the arc chamber outer cover; a first distance sensor, which is attached to the arc chamber outer cover and used to measure a consumption depth of the repeller in the travel direction; and a second distance sensor, which is attached to the arc chamber outer cover and used to measure a consumption depth of the cathode in the travel direction.

[0140] The foregoing summarizes the features of several embodiments so that those skilled in the art can better understand the aspects of the present disclosure. Those skilled in the art should understand that multiple technicians can easily use the present disclosure as a basis for designing or modifying other processes and structures for achieving the same purpose and / or achieving the same advantages as the embodiments introduced herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and multiple technicians can make various changes, substitutions and modifications herein without departing from the spirit and scope of the present disclosure.

Claims

1. An ion generator for an ion implanter, characterized in that: Include: an arc chamber defined by an arc chamber outer cover extending in a direction of travel; a filament for generating a plurality of hot electrons; a cathode disposed at a first end of the arc chamber housing in the direction of travel and configured to generate a plurality of secondary electrons in response to bombardment by a plurality of thermal electrons generated by the filament; and A repeller is disposed at a second end of the arc chamber outer housing opposite to the first end in the traveling direction, wherein the repeller is movable relative to the arc chamber outer housing.

2. The ion generator of the ion implanter according to claim 1, characterized in that: Further including: A first driving mechanism is coupled to the repeller and is used to move the repeller relative to the arc chamber outer cover.

3. The ion generator of the ion implanter according to claim 2, characterized in that: The first driving mechanism is coupled to the repeller via a shaft attached to the repeller.

4. The ion generator of the ion implanter according to claim 2, characterized in that: Further including: A first distance sensor is attached to the arc chamber outer cover and is used to measure a consumption depth of the repeller in the travel direction.

5. The ion generator of the ion implanter according to claim 4, characterized in that: Further including: A second driving mechanism is coupled to the cathode and is used to move the cathode relative to the arc chamber outer cover.

6. An ion generator for an ion implanter, characterized in that: Include: an arc chamber defined by an arc chamber outer cover extending in a direction of travel; a filament for generating a plurality of hot electrons; a cathode disposed at a first end of the arc chamber housing in the direction of travel and configured to generate a plurality of secondary electrons in response to bombardment by a plurality of thermal electrons generated by the filament; and A repeller is disposed at a second end of the arc chamber outer cover opposite to the first end in the traveling direction, wherein the repeller is curved.

7. The ion generator of the ion implanter according to claim 6, characterized in that: The repelling electrode includes: a front surface, the front surface facing the cathode; and a rear surface, the rear surface being opposite to the front surface; and The front surface is a concave surface when viewed from the cathode, and the rear surface is a convex surface when viewed toward the cathode.

8. The ion generator of the ion implanter according to claim 7, characterized in that: Further including: A first driving mechanism is coupled to the repeller and is used to move the repeller relative to the arc chamber outer cover.

9. An ion generator for an ion implanter, characterized in that: Include: an arc chamber defined by an arc chamber outer cover extending in a direction of travel; a filament for generating a plurality of hot electrons; a cathode disposed at a first end of the arc chamber housing in the direction of travel and configured to generate a plurality of secondary electrons in response to bombardment by a plurality of thermal electrons generated by the filament; a repeller disposed at a second end of the arc chamber outer housing opposite to the first end in the travel direction, wherein the repeller is movable relative to the arc chamber outer housing and is curved; and A first drive mechanism is coupled to the repeller and used to move the repeller relative to the arc chamber outer cover, wherein the first drive mechanism is coupled to the repeller via a shaft attached to the repeller, and the first drive mechanism is an actuator, a track, a continuous track or a stepping motor.

10. The ion generator of the ion implanter according to claim 9, characterized in that: Further including: a second drive mechanism coupled to the cathode and configured to move the cathode relative to the arc chamber outer cover; a first distance sensor attached to the arc chamber outer housing and used to measure a consumption depth of the repeller in the travel direction; and A second distance sensor is attached to the arc chamber outer cover and is used to measure a consumption depth of the cathode in the travel direction.

Images