Improving chemical utilization by increasing pressure during substrate processing

Abstract

A substrate processing system includes a processing chamber including a susceptor to support a substrate. The process chamber includes a showerhead configured to supply a precursor during a dosing step of an atomic layer deposition (ALD) process and a purge gas during a purge step thereof to process a substrate. The burdening step and the cleaning step include an order in which the cleaning step is followed after the burdening step. The substrate processing system includes a throttle valve connected to the processing chamber and a vacuum pump connected to the throttle valve. The substrate processing system includes a controller configured to control the vacuum pump, open the throttle valve during the sweeping step, and close the throttle valve during at least a portion of the dosing step to increase pressure within the processing chamber during at least the portion of the dosing step of the ALD process.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 413,777, filed on October 6, 2022. The entire disclosure of the above-referenced application is incorporated herein by reference. Technical Field

[0002] The present disclosure relates generally to substrate processing systems, and more particularly to systems and methods for improving chemical utilization by increasing pressure during substrate processing. Background Art

[0003] The background description provided here is for the purpose of generally presenting the background of the present disclosure. The work of the currently designated inventors within the scope described in this background section and aspects of the specification that were not determined to be prior art at the time of filing the application are neither explicitly nor implicitly admitted to be prior art against the present disclosure.

[0004] Atomic layer deposition (ALD) is a thin film deposition method that sequentially performs gaseous chemical processes to deposit a thin film on the surface of a material (e.g., the surface of a substrate such as a semiconductor wafer). Most ALD processes use at least two chemicals called precursors (reactants) that react with the material surface one at a time in a continuous, self-limiting manner. For example, a typical ALD process includes a series of sequential and repeated batching and sweeping steps. Through repeated exposure to different precursors, a thin film is gradually deposited on the surface of the material.

[0005] Thermal ALD (T-ALD) processes are typically performed in a heated processing chamber. The processing chamber is maintained at a pressure below atmospheric pressure using a vacuum pump and a controlled flow of inert gas (called a trickle). The substrate to be coated with the film is placed in the processing chamber and allowed to equilibrate with the temperature of the processing chamber before starting the ALD process. The plasma enhanced ALD (PEALD) process uses plasma in the batching step. The plasma can be generated in situ in the processing chamber. Alternatively, the plasma can be generated away from the processing chamber and then supplied to the processing chamber. Summary of the invention

[0006] A substrate processing system includes a processing chamber, the processing chamber including a susceptor, the susceptor being configured to support a substrate. The processing chamber includes a showerhead, the showerhead being configured to supply a precursor during a dosing step of an atomic layer deposition (ALD) process and to supply a purge gas during a sweeping step of the ALD process to process the substrate. The dosing step and the purge step include a sequence in which a subsequent purge step is performed after the dosing step. The substrate processing system includes a throttle valve connected to the processing chamber; and a vacuum pump connected to the throttle valve. The substrate processing system includes a controller configured to control the vacuum pump, open the throttle valve during the purge step, and close the throttle valve during at least a portion of the dosing step to increase the pressure in the processing chamber during the at least a portion of the dosing step of the ALD process.

[0007] In additional features, in the sequence, the controller closes the throttle valve after initiating the dosing step and before initiating the subsequent purging step, opens the throttle valve at the end of the dosing step, maintains the throttle valve open throughout the subsequent purging step until after initiating the subsequent dosing step, and closes the throttle valve after initiating the subsequent dosing step.

[0008] In additional features, in the sequence, the controller closes the throttle valve during the entire dosing step and opens the throttle valve during the entire subsequent purge step.

[0009] In additional features, in the sequence, the controller closes the throttle valve from the beginning to the end of the dosing step and opens the throttle valve from the beginning to the end of the subsequent purge step.

[0010] In additional features, in the sequence, the controller closes the throttle valve for a predetermined time period at the end of the dosing step, opens the throttle valve at the end of the predetermined time period and before the subsequent scavenging step begins, maintains the throttle valve open during the subsequent scavenging step until the end of the subsequent dosing step, and closes the throttle valve at the end of the subsequent dosing step.

[0011] In additional features, in the sequence, the controller closes the throttle valve for a predetermined time period before the end of the dosing step, opens the throttle valve at the end of the predetermined time period and before the subsequent scavenging step begins, maintains the throttle valve open during the subsequent scavenging step until before the end of the subsequent dosing step, and closes the throttle valve before the end of the subsequent dosing step.

[0012] In additional features, the controller is configured to control a speed at which the throttle valve opens and closes.

[0013] In additional features, the controller is configured to, at least in part, open and close the throttle valve at different speeds.

[0014] In additional features, the controller is configured to open and close the throttle valve at least partially in a pulsed manner.

[0015] In additional features, the controller is configured to open and close the throttle valve at least partially at different speeds and at least partially in a pulsed manner.

[0016] In additional features, the substrate processing system further includes: a gas delivery system configured to supply an inert gas to the processing chamber during the ALD process.

[0017] In additional features, the substrate processing system further comprises: a gas delivery system configured to supply the precursor to the showerhead during the dosing step and to supply the purge gas during the purge step.

[0018] In additional features, the substrate processing system further includes: a plasma generator disposed outside the processing chamber. The plasma generator is configured to generate plasma and supply the plasma to the processing chamber through the showerhead during the ALD process.

[0019] In additional features, the controller is configured to activate the vacuum pump during the ALD process.

[0020] In still other features, a method for processing a substrate on a susceptor disposed in a substrate processing system includes supplying a precursor during a dosing step of an atomic layer deposition (ALD) process and supplying a purge gas to a showerhead disposed in the substrate processing system to process the substrate during a purge step of the ALD process. The dosing step and the purge step include a sequence in which a dosing step is followed by a subsequent purge step. The method includes opening a throttle valve connected to the processing chamber and a vacuum pump during the purge step; and closing the throttle valve during at least a portion of the dosing step to increase a pressure within the processing chamber during the at least a portion of the dosing step of the ALD process.

[0021] In additional features, in the sequence, closing the throttle valve during the at least a portion of the dosing step includes closing the throttle valve after starting the dosing step and before starting the subsequent purging step. The method also includes: opening the throttle valve at the end of the dosing step; maintaining the throttle valve open throughout the subsequent purging step until after starting the subsequent dosing step; and closing the throttle valve after starting the subsequent dosing step.

[0022] In additional features, in the sequence, closing the throttle valve during the at least a portion of the dosing step includes closing the throttle valve during the entirety of the dosing step, the method further comprising opening the throttle valve during the entirety of the subsequent purging step.

[0023] In additional features, in the sequence, closing the throttle valve during the at least a portion of the dosing step includes closing the throttle valve from the beginning to the end of the dosing step, and the method further includes opening the throttle valve from the beginning to the end of the subsequent purging step.

[0024] In additional features, in the sequence, closing the throttle valve during the at least a portion of the batching step includes closing the throttle valve for a predetermined time period at the end of the batching step. The method also includes: opening the throttle valve at the end of the predetermined time period and before the subsequent purge step begins; maintaining the throttle valve open during the subsequent purge step until the end of the subsequent batching step; and closing the throttle valve at the end of the subsequent batching step.

[0025] In additional features, in the sequence, closing the throttle valve during the at least a portion of the dosing step includes closing the throttle valve for a predetermined time period before the end of the dosing step. The method further includes: opening the throttle valve at the end of the predetermined time period and before the start of the subsequent purge step; maintaining the throttle valve open during the subsequent purge step until before the end of the subsequent dosing step; and closing the throttle valve before the end of the subsequent dosing step.

[0026] In additional features, the method further comprises controlling a speed at which the throttle valve opens and closes.

[0027] In additional features, the method further comprises at least partially opening and closing the throttle valve at different speeds.

[0028] In additional features, the method further comprises at least partially pulsing opening and closing the throttle valve.

[0029] 24. The method of claim 15, further comprising opening and closing the throttle valve at least partially at different speeds and at least partially in a pulsed manner.

[0030] In additional features, the method further includes supplying an inert gas to the processing chamber during the ALD process.

[0031] In additional features, the method further includes generating a plasma remotely from the processing chamber and supplying the plasma to the processing chamber through the showerhead during the ALD process.

[0032] In additional features, the method further includes activating the vacuum pump during the ALD process.

[0033] Further scope of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0035] Figure 1 An example of a substrate processing system for processing a substrate using a high pressure step during atomic layer deposition (ALD) according to the present disclosure is shown;

[0036] Figure 2 and 3A -3D shows an example of an ALD process according to the present disclosure, the ALD process comprising Figure 1 a high pressure step for processing a substrate in a substrate processing system of

[0037] Figure 4 According to the present disclosure Figure 1 An example of a method of processing a substrate using a substrate processing system using an ALD process, the ALD process comprising Figure 2 and Figures 3A-3D High pressure steps shown.

[0038] Among the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0039] In tools using atomic layer deposition (ALD) processes, chemical consumption of precursors is often not well optimized, resulting in high chemical costs. The reason for the high chemical costs is the slow chemical adsorption of precursors to the substrate surface. Due to the slow chemical adsorption, long precursor dosing times are often used. However, a large amount of the precursor used is not chemically adsorbed, but is wasted (scavenged), thus increasing chemical costs.

[0040] A higher degree of utilization of precursor chemicals is needed to reduce chemical costs. Shorter precursor batching times can be used to reduce costs. However, shorter batching times can have an adverse effect on deposition rates and tool throughput. In order to compensate for the lower batching time of the precursor (i.e., to prevent the adverse effects of using a lower batching time), the present disclosure adds a higher pressure step to the recipe, which results in a more efficient consumption of the precursor.

[0041] Specifically, a high pressure step is added after the dosing step and before the subsequent sweeping step (i.e., between the dosing step and the subsequent sweeping step). The high pressure step includes closing a throttle valve connected between the process chamber and the vacuum pump to maintain the pressure in the process chamber. The high pressure step increases the adsorption of the precursor on the substrate. Using the high pressure step, the deposition rate and tool throughput can be maintained while keeping the chemical usage low.

[0042] More specifically, in the method of the present disclosure, the precursor dosing time is reduced, and a high pressure step is added after the precursor dosing but before the precursor purge step. The high pressure step includes closing the throttle valve so that the precursor stays in the process chamber longer, which can consume chemicals more efficiently. The high pressure step significantly reduces the amount of chemicals used while maintaining high deposition rates and throughput.

[0043] Therefore, adding a high pressure step to the ALD recipe can provide higher chemical utilization during deposition, thereby reducing the chemical usage and chemical cost of the deposition process. The high pressure step after the formulation according to the present disclosure can be added to any ALD process to efficiently utilize chemicals and reduce chemical waste. These and other features of the present disclosure are described in more detail below.

[0044] The content of this disclosure is organized as follows. Figure 1 An example of a substrate processing system for processing a substrate using an ALD process including a high pressure step according to the present disclosure is described. Figure 2 and Figures 3A-3D An example of using an ALD process including a high pressure step according to the present disclosure is described. Figure 4 An example of a method for processing a substrate using an ALD process including a high pressure step according to the present disclosure is described. Examples of Substrate Handling Systems

[0045] Figure 1An example of a substrate processing system 100 according to the present disclosure is shown. The substrate processing system 100 includes a plasma source 102 and a processing chamber 103. The plasma source 102 may be dome-shaped as shown or may be any other shape. The processing chamber 103 includes a pedestal 112 and a showerhead 104. The pedestal 112 is disposed within the processing chamber 103. The showerhead 104 is disposed above the pedestal 112 and at the top of the processing chamber 103.

[0046] The plasma source 102 is arranged above the showerhead 104 to generate a remote plasma 142, as described in detail below. The showerhead 104 is arranged between the plasma source 102 and the processing chamber 103. The showerhead 104 separates the plasma source 102 from the processing chamber 103. Therefore, the plasma source 102 is arranged outside the processing chamber 103 and away from the processing chamber 103. Therefore, the plasma generated in the plasma source 102 is called a remote plasma 142.

[0047] The spray head 104 is described in detail below. In short, the spray head 104 is made of metal (e.g., aluminum) or an alloy. The spray head 104 includes a planar base 105 and a cylindrical portion 107 extending vertically downward from the base 105. The base 105 extends radially outward at the top of the cylindrical portion 107 to form a flange 111. The cylindrical portion 107 has an outer wall 109-1 and an inner wall 109-2. The inner wall 109-2 of the cylindrical portion 107 defines the hole 106 of the spray head 104. The diameter of the hole 106 is equal to the diameter of the inner wall 109-2 of the cylindrical portion 107 of the spray head 104 (i.e., the ID of the cylindrical portion 107).

[0048] The process chamber 103 includes a side wall 108 and a bottom wall 110. The side wall 108 is attached to the bottom of the cylindrical portion 107 of the showerhead 104. The side wall 108 is perpendicular to the base 105 of the showerhead 104 and extends vertically downward from the bottom of the outer wall 109-1 of the cylindrical portion 107 of the showerhead 104. The bottom wall 110 of the process chamber 103 is attached to the side wall 108 of the process chamber 103. The bottom wall 110 is parallel to the base 105 of the showerhead 104 and perpendicular to the side wall 108 of the process chamber 103.

[0049] The pedestal 112 is arranged directly below the showerhead 104 in the process chamber 103. During the process, the substrate 114 is arranged on the top surface 116 of the pedestal 112. The top surface 116 of the pedestal 112 is flat and parallel to the base 105 of the showerhead 104 and to the bottom wall 110 of the process chamber 103. Therefore, the substrate 114 is parallel to the top surface 116 of the pedestal 112, the base 105 of the showerhead 104, and the bottom wall 110 of the process chamber 103. The ID of the cylindrical portion 107 of the showerhead 104 (i.e., the diameter of the inner wall 109-2 of the showerhead 104) is greater than the OD of the top surface 116 of the pedestal 112. The ID of the cylindrical portion 107 of the showerhead 104 (i.e., the diameter of the inner wall 109-2 of the showerhead 104) is also greater than the OD of the substrate 114.

[0050] An actuator 120 driven by a motor 122 can move the base 112 vertically up and down relative to the spray head 104 within the cylindrical portion 107 of the spray head 104. The gap between the bottom of the base 105 of the spray head 104 and the top surface 116 of the base 112 can be adjusted by vertically moving the base 112 within the cylindrical portion 107 of the spray head 104. For example, the gap between the bottom of the base 105 of the spray head 104 and the top surface 116 of the base 112 can be approximately 0.2 inches, 0.15 inches, or 0.11 inches.

[0051] The bottom end of the plasma source 102 is open and attached to the top end of the first cylindrical member 124. The first cylindrical member 124 is arranged at the periphery of the planar base 105 of the showerhead 104. The first cylindrical member 124 includes a first flange 126. The first flange 126 extends radially outward from the approximate center of the first cylindrical member 124. Therefore, the first cylindrical member 124 has the shape of the letter "T" rotated 90 degrees to the left.

[0052] The second cylindrical member 128 surrounds the first cylindrical member 124. The second cylindrical member 128 includes a second flange 129 extending radially inward from the bottom end of the second cylindrical member 128. Therefore, the second cylindrical member 128 has a shape of a horizontally inverted letter "L". The first flange 126 of the first cylindrical member 124 is suspended above the second flange 129 of the second cylindrical member 128. The bottom ends of the first cylindrical member 124 and the second cylindrical member 128 are attached to the top of the base 105 of the spray head 104 near the periphery of the base 105 of the spray head 104.

[0053] The substrate processing system 100 includes a gas delivery system 130. The gas delivery system 130 includes one or more gas sources 150-1, 150-2, ..., and 150-N (collectively referred to as gas sources 150), where N is an integer greater than 1. The gas source 150 supplies one or more process gases, purge gases (e.g., inert gases), cleaning gases, etc. The gas source 150 is connected to mass flow controllers 154-1, 154-2, ..., and 154-N (collectively referred to as mass flow controllers 154) through corresponding valves 152-1, 152-2, ..., and 152-N (collectively referred to as valves 152). The MFC 154 controls the mass flow rate of the gas supplied by the gas source 150. The MFC 154 supplies the gas to the manifold 156.

[0054] The plasma source 102 includes a gas injector 132 disposed at the top of the plasma source 102. The gas injector 132 is connected to a manifold 156. The gas injector 132 receives one or more gases from a gas delivery system 130 via the manifold 156. The gas injector 132 supplies the one or more gases received from the gas delivery system 130 into the plasma source 102 via the manifold 156. The plasma source 102 generates a remote plasma 142 (i.e., a plasma generated outside the processing chamber 103) as described below.

[0055] The coil 134 is arranged around the plasma source 102. A first end of the coil 134 is grounded, and a second end of the coil 134 is connected to an RF generation system 136. The RF generation system 136 includes an RF generator 138 that generates RF power. The RF power is fed to the coil 134 by a matching network 140. The RF power supplied to the coil 134 ignites one or more gases injected into the plasma source 102 from the gas delivery system 130 by the gas injector 132, and generates a remote plasma 142 in the plasma source 102. Since the plasma source 102 generates plasma away from the processing chamber 103 (i.e., outside), the plasma generated in the plasma source 102 is called a remote plasma 142.

[0056] The showerhead 104 is now described in more detail. The showerhead 104 supplies gas received from the gas delivery system 130, the remote plasma 142 generated in the plasma source 102, or both from the plasma source 102 to the processing chamber 103. The base 105 of the showerhead 104 includes a first set of through holes (also referred to as free radical holes) 160-1, 160-2, ... and 160-N (collectively referred to as free radical holes 160), where N is an integer greater than 1. The free radical holes 160 extend from the top surface 162 of the base 105 of the showerhead 104 to the bottom surface 164 (also referred to as the face plate 164) of the base 105 of the showerhead 104 facing the substrate. Free radicals from the remote plasma 142 in the plasma source 102 pass through the free radical holes 160 into the processing chamber 103.

[0057] In addition, the base 105 of the showerhead 104 includes a plenum 166 that is separate from and not in fluid communication with the radical holes 160. The plenum 166 receives one or more precursor gases from the second gas delivery system 170 during the dosing step of the ALD process. During the purge step of the ALD process, the plenum 166 may also receive a purge gas (e.g., an inert gas) from the second gas delivery system 170. Optionally, the purge gas may be supplied by the gas delivery system 130 through the gas injector 132.

[0058] The base 105 of the showerhead 104 also includes a second set of holes (also referred to as precursor holes) 172-1, 172-2, ... and 172-N (collectively referred to as precursor holes 172), where N is an integer greater than 1. The precursor holes 172 extend from the plenum 166 to the faceplate 164 of the showerhead 104. One or more precursor gases supplied by the second gas delivery system 170 are supplied to the processing chamber 103 through the precursor holes 172. The free radical holes 160 are not in fluid communication with the plenum 166 and the precursor holes 172. The diameter and length of the free radical holes 160 are larger than the precursor holes 172.

[0059] The base 105 of the showerhead 104 also includes a plurality of grooves 168 - 1, 168 - 2, ..., and 168 -N (collectively referred to as grooves 168 ), where N is an integer greater than 1. The grooves 168 form cooling channels. The fluid delivery system 180 supplies coolant to the grooves 168 through an inlet (not shown) in the base 105 of the showerhead 104 .

[0060] One or more temperature sensors 169 are disposed in the base 105 of the spray head 104. The temperature sensors 169 are connected to a temperature controller 182. The temperature controller 182 controls the supply of coolant from the fluid delivery system 180 to the recess 168 to control the temperature of the spray head 104.

[0061] In addition, the susceptor 112 includes one or more heaters 184, a cooling system (not shown) that receives coolant from the fluid delivery system 180, and one or more temperature sensors 179. The temperature controller 182 is connected to the temperature sensor 179 in the susceptor 112. The temperature controller 182 controls the power supply to the heater 184. The temperature controller 182 controls the supply of coolant from the fluid delivery system 180 to the cooling system in the susceptor 112 to control the temperature of the susceptor 112.

[0062] The throttle valve 186 and the vacuum pump 188 control the pressure in the process chamber 103 and exhaust reactants from the process chamber 103 during the process. The system controller 190 controls the components of the above-mentioned substrate processing system 100. Specifically, the system controller 190 controls the throttle valve 186 to add a high pressure step according to the present disclosure during the processing of the substrate 114, as described in detail below. Example of adding a high pressure step

[0063] The substrate processing system 100 performs an ALD process on a substrate 114 using a high pressure step according to the present disclosure as follows. Figure 2 The high pressure step is described in detail in Figure 3. Figure 4 An example method including a high pressure step for processing the substrate 114 is described in detail.

[0064] Figure 2 and 3A -3D shows an example of an ALD process with and without an added high pressure step. Figure 2 The top half of the diagram (labeled “Poor Chemical Utilization”) shows and describes an example of an ALD process without a high pressure step to illustrate the problem that is solved by adding the high pressure step. Figure 2 The lower half of the Figures 3A-3D , an example of an ALD process including a high pressure step is shown and described to illustrate the solution provided by the present disclosure. Figure 2 and 3A -3D, the acronyms HP and TV represent the high pressure step and the throttle valve 186, respectively, as described below.

[0065] exist Figure 2In the upper half of FIG. 1 , the ALD process includes a sequence of dose steps and purge steps used during processing of the substrate 114. For example, the sequence includes a first dose step Dose 1, followed by a first purge step Purge 1, followed by a second dose step Dose 2, followed by a second purge step Purge 2, and so on. In the sequence, a first precursor is supplied to the showerhead 104 during the first dose step Dose 1, and a second precursor is supplied to the showerhead 104 during the second dose step Dose 2. A purge gas (e.g., and an inert gas) is supplied to the showerhead 104 during the first and second purge steps Purge 1 and Purge 2 to exhaust byproducts generated during the first and second dose steps Dose 1 and Dose 2 from the processing chamber 103. Dose 1 starts at time T0 and ends at time T2'. Purge 1 starts at time T2'. When purge step Purge 1 ends, the next dose step Dose 2 starts. The batching 2 step is followed by the sweeping 2 step, and so on.

[0066] The sequence of steps dose 1, purge 1, dose 2, and purge 2 is repeated, as shown by the Nth dose step dose N and the Nth purge step purge N, until the process of substrate 114 is completed. During the process, the throttle valve 186 is open and the vacuum pump 188 is started. This sequence does not use the high pressure steps of the present disclosure.

[0067] As mentioned above, Figure 2 The chemical consumption of precursors in the ALD process shown in the upper part leads to high chemical costs. The reason for the high chemical cost is the slow chemical adsorption of the precursors to the substrate surface. Due to the slow chemical adsorption, long precursor dosage times are usually used. However, a large amount of the precursor used is not chemically adsorbed, but is wasted (purged), thus increasing the chemical cost.

[0068] A higher degree of utilization of precursor chemicals is needed to reduce chemical costs. Although shorter precursor batching times can be used to reduce costs, shorter batching times can have an adverse effect on deposition rates and tool throughput. In order to compensate for the lower batching time of the precursor (i.e., to prevent the adverse effects of using a lower batching time), the present disclosure adds a higher pressure step to the process recipe as described below, which results in a more efficient consumption of the precursor (e.g., Figure 2 The lower half and Figures 3A-3D shown).

[0069] exist Figure 2 The lower half and Figures 3A-3D In FIG. 1 , an ALD process including an added high pressure step according to the present disclosure is shown. Figure 2 and Figures 3A-3DThe ALD process includes the same Figure 2 The order of batching and cleaning steps is essentially the same as that described in the first half, with two exceptions. First, the batching time (i.e., the duration of each batching step) is changed from Figure 2 The upper part (T0 to T2') is reduced to Figure 2 The lower part shows (T0-T2), where T2 is less than T2'. Figure 2 The duration of each batching step in the lower half (T0-T2) is less than Figure 2 The duration of each dosing step in the upper half (T0 to T2'). Secondly, a high pressure step (described below) is added as described below after the start of each dosing step and before the start of the subsequent sweep step (ie between each dosing step and the subsequent sweep step).

[0070] For example, a first implementation of the high pressure (HP) step is as follows Figure 2 Lower half and Figure 3A Other implementations of the high pressure step are described below. Figure 3B-3D Display and describe. Figure 3A In the first implementation shown, the high pressure step starts at time T1 after the batching step starts at time T0 and before the batching step ends at time T2 (i.e. before the subsequent sweeping step starts at time T2). The high pressure step ends at time T2 (i.e. at the end of the batching step Dose 1 and at the beginning of the subsequent sweeping step Sweep 1). The duration of the high pressure step is equal to (T2-T1). That is, the high pressure step is added during a portion of the batching step Dose 1 and before the subsequent sweeping step Sweep 1 starts at time T2. Therefore, the high pressure step is added between the batching step Dose 1 and the subsequent sweeping step Sweep 1. The high pressure step is added to the rest of the batching and sweeping step sequence using the same procedure.

[0071] Alternatively, in Figure 3B In the second implementation shown, the high pressure step may start when the batching step batch 1 starts at time T0, and may end when the batching step batch 1 ends at time T2, at which time the subsequent sweep step sweep 1 starts. In the second implementation, the duration of the high pressure step is equal to (T2-T0). That is, the high pressure step is added during the entire batching step batch 1 and before the subsequent sweep step sweep 1 starts at time T2. The high pressure step is added to the rest of the batching and sweeping step sequence of the ALD process using the same procedure.

[0072] exist Figure 3CIn the third implementation shown, the high pressure step may be started when the batching step batching 1 ends at time T2. After the batching step batching 1 ends at time T2, the subsequent sweeping step sweeping 1 may be delayed for a predetermined time period. At time (T2 + predetermined time period), the high pressure step may be ended and the subsequent sweeping step sweeping 1 may be started. In the third implementation, the duration of the high pressure step is equal to the predetermined time period. That is, the high pressure step is added after the batching step ends and before the subsequent sweeping step begins. Therefore, in the third implementation, the high pressure step is added between the batching step and the subsequent sweeping step. The same procedure is used to add the high pressure step to the rest of the batching and sweeping step sequence of the ALD process.

[0073] exist Figure 3D In the variation of the third implementation shown, the high pressure step can be started slightly before the batching step batching 1 ends at time T2. The rest of this variation can be similar to the rest of the third implementation described above, except that since the high pressure step starts slightly earlier, the duration of the high pressure step will be slightly longer than the predetermined time period.

[0074] Typically, the high pressure step is added between the batching step and the subsequent sweeping step. Depending on the implementation, the high pressure step can overlap with the batching step. For example, in a first implementation (such as Figure 3A ) and a variation of the third implementation (as shown Figure 3D In one embodiment, the high pressure step partially overlaps with the batching step, while in a second embodiment, the high pressure step completely overlaps with the batching step (as shown in FIG. Figure 3B ). Regardless of the implementation scheme used, the high pressure step precedes the sweep step, which follows the batching step in the order of batching and sweeping steps of the ALD process. Throughout this disclosure, a subsequent sweeping step is a sweeping step following a previous batching step. In other words, the i-th sweeping step follows the i-th batching step.

[0075] The high pressure step is added to maintain the high pressure in the process chamber 103 during or after the dosing step (depending on the implementation using the high pressure step) and before the subsequent purge step. The high pressure step allows the precursor supplied in the dosing step to remain in the process chamber 103, thus allowing for shorter dosing times and reducing chemical costs without sacrificing deposition rate and tool throughput.

[0076] For each dosing step and subsequent sweep step, the procedure of adding a high pressure step is repeated in the order of dosing and sweeping steps in the ALD process. Figure 2 The times T0, T1, and T2 are shown in FIG. 1 to illustrate the high pressure step for only one batching step, but similar times may be used, respectively (e.g., Figure 3AThe high pressure step is added for each subsequent dosing and cleaning step in a repeated sequence at times T4, T5, and T6 as shown in FIG. 1 until processing of the substrate 114 is complete.

[0077] The high pressure in the process chamber 103 provided by the added high pressure step may result in a higher utilization of the precursor chemicals, thereby reducing the chemical cost. Specifically, due to the high pressure in the process chamber 103 provided by the added high pressure step, a shorter precursor dosing time ((T2-T0)) is provided, compared to (T2'-T0) without the high pressure step, such as Figure 2 The higher pressure step (shown in the upper part) can be used to reduce costs. The shorter dosing time does not adversely affect the deposition rate and tool throughput because the shorter dosing time is compensated by the high pressure step, which increases the chemical adsorption rate of the precursor despite the shorter dosing time. Therefore, the high pressure step leads to shorter dosing time, higher precursor chemical utilization, and lower chemical costs without sacrificing deposition rate and tool throughput.

[0078] The high pressure in the processing chamber 103 is achieved in the following manner. Figure 2 Lower half and Figure 3A In the first implementation of the high pressure step shown, the high pressure step begins at time T1 and ends at time T2. The high pressure in the process chamber 103 is achieved by closing the throttle valve 186 from time T1 to time T2. Specifically, the throttle valve 186 is opened from time T0 to time T1, closed from T1 to time T2, and opened at time T2. The throttle valve 186 remains open from time T2 throughout the subsequent purge step until the next high pressure step begins (e.g., until the next high pressure step begins). Figure 3A The high pressure step is started at time T3 after the next batching step is started (i.e., the throttle valve 186 is closed). The above-mentioned procedure of opening and closing the throttle valve 186 is repeated until the processing of the substrate 114 is completed.

[0079] During the high pressure step, when the throttle valve 186 is closed, the pressure in the process chamber may increase due to a variety of factors. For example, the process chamber 103 is not evacuated during the high pressure step because the throttle valve 186 is closed. In addition, during the high pressure step, a controlled flow of some gas, such as an inert gas (referred to as a trickle), continues to flow through the process chamber 103 (e.g., through the nozzle 104). The controlled flow of these gases increases the pressure in the process chamber 103 because the process chamber 103 is not evacuated during the high pressure step due to the throttle valve 186 being closed. In addition, process byproducts produced during the dosing step that are not discharged from the process chamber 103 due to the throttle valve 186 being closed also cause the pressure in the process chamber 103 to increase. Therefore, the pressure in the process chamber 103 increases during the high pressure step (e.g., from Figure 3AThe time T1 to T2 is shown increasing from P1 to P2. Since the throttle valve 186 is closed, the high pressure step causes the precursor to remain in the process chamber 103 for a longer time (soak), allowing for more efficient consumption of the chemicals.

[0080] At the end of the high pressure step, throttle valve 186 is opened from time T2 to T3 (eg, Figure 3A ), and vacuum pump 186 during subsequent purge steps (e.g., from Figure 3A 2 to T3) to evacuate the process chamber 103. Thus, during a subsequent purge step (e.g., Figure 3A From time T2 to T3 as shown, the pressure in the process chamber 103 decreases from P2 to P1.

[0081] Although the pressure in the processing chamber 103 increases and decreases Figure 3A 186 is shown linearly, but the throttle valve 186 can be opened and closed gradually in other ways (e.g., nonlinearly). The pressure increase and decrease in the processing chamber 103 can be gradually changed according to the opening and closing speed of the throttle valve 186. It can be (for example, by Figure 1 The system controller 190 shown controls the speed at which the throttle valve 186 closes and opens to control the rate at which the pressure in the process chamber 103 increases and decreases. The rate at which the pressure in the process chamber 103 increases and decreases is proportional to the speed at which the throttle valve 186 opens and closes.

[0082] In some examples, instead of gradually operating, throttle valve 186 may be operated by Figure 1 The system controller 190 shown opens and closes in a step or pulsed manner. In other examples, the throttle valve 186 can be opened and closed at different speeds. In a further example, the throttle valve 186 can be opened and closed using a combination of gradual operation and step or pulse operation. In addition, the throttle valve 186 can be opened at different speeds. For example, the throttle valve 186 can be partially opened at a first speed, while the rest of the throttle valve 186 can be opened at a second speed. Similarly, the throttle valve 186 can be partially closed at a first speed, while the rest of the throttle valve 186 can be closed at a second speed. In addition, step or pulse operation can be used during the partial opening and partial closing of the throttle valve 186 and / or the opening and closing of the rest of the throttle valve 186.

[0083] Alternatively, the throttle valve 186 may be closed and opened at different times to implement the high pressure step, depending on the implementation scheme of the high pressure step. Figure 3BIn the second implementation of the high pressure step shown, the high pressure of the processing chamber 103 can be achieved by closing the throttle valve 186 from time T0 to time T2 (i.e., throughout the entire dosing step). The throttle valve 186 is opened from time T2 to time T3 (i.e., throughout the purge step after the dosing step). The procedure of repeatedly opening and closing the throttle valve 186 continues throughout the subsequent dosing and purge steps until the processing of the substrate 114 is completed.

[0084] In the above description and Figure 3C In the third implementation of the high pressure step shown, the high pressure in the process chamber 103 can be achieved by closing the throttle valve 186 at time T2 (i.e., at the end of the dosing step). The throttle valve 186 is closed for a predetermined time period from time T2 until the subsequent purge step begins. The throttle valve 186 is opened at the beginning of the subsequent purge step. The procedure of repeatedly opening and closing the throttle valve 186 continues throughout the subsequent dosing and purge steps until the processing of the substrate 114 is completed.

[0085] In the above description and Figure 3D In a variation of the third implementation of the high pressure step shown, the high pressure in the processing chamber 103 can be achieved by closing the throttle valve 186 a little before the end of the dosing step Dosing 1 at time T2. The throttle valve 186 is opened until a little before the end of the dosing step at time T2. The throttle valve 186 remains closed from a little before time T2 until a predetermined time period after time T2, until the subsequent purge step begins. The throttle valve 186 is opened at the beginning of the subsequent purge step. The procedure of repeatedly opening and closing the throttle valve 186 continues throughout the subsequent dosing and purge steps until the processing of the substrate 114 is completed.

[0086] exist Figure 2 Lower half and Figures 3A-3D In the ALD process, along with the batching steps batch 1 to batch N, the sweeping steps sweep 1 to sweep N, and the high pressure step HP, the duration of opening and closing of the throttle valve 186 is indicated by the labels TV on (or TVO) and TV off (or TVC). The vacuum pump 188 is turned on throughout the ALD process including the batching, sweeping, and high pressure steps. The pressure P1 is close to vacuum and the pressure P2 is slightly above vacuum. In the high pressure step, the pressure P2 can also be achieved by partially closing the throttle valve 186. Therefore, throughout the present disclosure, the description of closing the throttle valve 186 also includes partially closing the throttle valve 186.

[0087] In all implementations of the high pressure step described above, the increase in pressure in the process chamber 103 is achieved because of the factors described with reference to the first implementation of the high pressure step described above. Since the throttle valve 186 is closed, the high pressure step causes the precursor to stay in the process chamber 103 for a longer time (soak), thereby allowing for more efficient consumption of chemicals. In addition, in these implementations, the throttle valve 186 can be controlled in the manner described with reference to the first implementation of the high pressure step. Therefore, in these implementations, the rate at which the pressure in the process chamber 103 increases and decreases is proportional to the speed at which the throttle valve 186 is closed and opened. Method to add high pressure step

[0088] Figure 4 It is shown that according to the present disclosure Figure 1 An example of a method 300 for processing a substrate 114 in a substrate processing system using a method comprising Figure 2 and the ALD process of the high pressure step shown in Figure 3. For example, the system controller 190 of the substrate processing system 100 executes the method 300 as follows.

[0089] At 302, conditions for performing an ALD process on a substrate 114 are established in a process chamber 103. For example, if a thermal ALD process is to be performed on the substrate 114, the pedestal 112 and the showerhead 104 are heated. If a PEALD process is to be performed on the substrate 114, a remote plasma 142 is generated in the plasma source 102. The throttle valve 186 is opened, and the vacuum pump 188 is turned on to evacuate the process chamber. The substrate 114 is loaded into the process chamber 103.

[0090] At 304, the system controller 190 controls the second gas delivery system 170 to supply a dose of the precursor into the process chamber 103. At 306, according to the implementation scheme for adding the high pressure step, the system controller 190 controls the second gas delivery system 170 to supply a dose of the precursor into the process chamber 103. Figure 2 The throttle valve 186 is closed at an appropriate time between the batching step and the subsequent purge step as described in FIG. 3 .

[0091] At 308, the system controller 190 determines whether it is time to perform the purge step. At 310, if it is time to perform the purge step, the system controller 190 opens the throttle valve 186, as described above with reference to Figure 2 3 . At 312 , the vacuum pump 188 purges the process chamber 103 .

[0092] At 314, the system controller 190 determines whether processing of the substrate 114 is complete. If processing of the substrate 114 is complete, the method 300 ends. If processing of the substrate 114 is not complete, the method 300 repeats steps 304 to 312. When repeating steps 304 to 312, the method proceeds as described above with reference to FIG. Figure 2 and 3 to select the appropriate precursor. In addition, throughout the method 300, the system controller 190 also controls the flow of other gases (such as inert gases or trickles) to maintain the high pressure during the high pressure step.

[0093] The foregoing description is merely illustrative in nature and is in no way intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because other modifications will become apparent upon studying the drawings, description and appended claims.

[0094] It should be understood that one or more steps in the method may be performed in different orders (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure may be implemented in the features of any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the permutation of one or more embodiments with respect to each other remains within the scope of the present disclosure.

[0095] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless the relationship between a first and a second element is explicitly described as "direct," when such a relationship is described in the above disclosure, the relationship can be a direct relationship, in which there are no other intervening elements between the first and second elements, but can also be an indirect relationship, in which there are one or more intervening elements (spatially or functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C), using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0096] In some implementations, the controller is part of a system, which may be part of the above examples. Such a system may include a semiconductor processing device, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of semiconductor wafers or substrates. The electronics may be referred to as a "controller," which may control various components or subcomponents of one or more systems.

[0097] Depending on the processing requirements and / or system type, the controller can be programmed to control any of the processes disclosed herein, including the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer into and out of tools and other transfer tools and / or load locks connected or docked with a particular system.

[0098] Broadly speaking, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that stores program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software).

[0099] Program instructions may be instructions sent to a controller in the form of various individual settings (or program files) that define operating parameters for performing a particular process on or for a semiconductor wafer or system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0100] In some implementations, the controller can be part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller can be in the "cloud" or all or part of a wafer fab host system that can allow remote access to wafer processing. The computer can enable remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, examine trends or performance criteria for multiple manufacturing operations, change parameters of a current process, set processing steps to follow a current process, or start a new process.

[0101] In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network (which may include a local network or the Internet). The remote computer may include a user interface that enables input or programming of parameters and / or settings, which are then sent from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control.

[0102] Thus, as described above, the controller may be distributed, for example, by including one or more discrete controllers networked together and working toward a common purpose, such as the processes and controls described herein. An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber that communicate with one or more integrated circuits remotely (e.g., at a platform level or as part of a remote computer), which combine to control the process on the chamber.

[0103] Example systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used in the manufacture and / or preparation of semiconductor wafers.

[0104] As described above, depending on one or more processing steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or tools used in material transport to transport wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

Claims

1. A substrate processing system, comprising: a processing chamber comprising a susceptor configured to support a substrate and a showerhead configured to supply a precursor during a dosing step of an atomic layer deposition (ALD) process and to supply a sweep gas during a sweeping step of the ALD process to process the substrate, wherein the dosing step and the sweeping step comprise a sequence in which a dosing step is followed by a subsequent sweeping step; a throttle valve connected to the process chamber; a vacuum pump connected to the throttle valve; and A controller is configured to control the vacuum pump, open the throttle valve during the purge step, and close the throttle valve during at least a portion of the dosing step to increase the pressure in the processing chamber during at least a portion of the dosing step of the ALD process.

2. The substrate processing system of claim 1 , wherein in the sequence, the controller closes the throttle valve after starting the dosing step and before starting the subsequent purge step, opens the throttle valve at the end of the dosing step, maintains the throttle valve open throughout the subsequent purge step until after starting the subsequent dosing step, and closes the throttle valve after starting the subsequent dosing step.

3. The substrate processing system of claim 1, wherein in the sequence, the controller closes the throttle valve throughout the dosing step and opens the throttle valve throughout the subsequent purge step.

4. The substrate processing system according to claim 1, wherein in the sequence, the controller closes the throttle valve during a period from the start to the end of the dosing step, and opens the throttle valve during a period from the start to the end of the subsequent purge step.

5. The substrate processing system of claim 1 , wherein in the sequence, the controller closes the throttle valve for a predetermined time period at the end of the dosing step, opens the throttle valve at the end of the predetermined time period and before the start of the subsequent cleaning step, maintains the throttle valve open during the subsequent cleaning step until the end of the subsequent dosing step, and closes the throttle valve at the end of the subsequent dosing step.

6. A substrate processing system according to claim 1, wherein in the sequence, the controller closes the throttle valve for a predetermined time period before the end of the dosing step, opens the throttle valve at the end of the predetermined time period and before the start of the subsequent cleaning step, maintains the throttle valve open during the subsequent cleaning step until before the end of the subsequent dosing step, and closes the throttle valve before the end of the subsequent dosing step.

7. The substrate processing system of claim 1, wherein the controller is configured to control a speed at which the throttle valve is opened and closed.

8. The substrate processing system of claim 1, wherein the controller is configured to, at least in part, open and close the throttle valve at different speeds.

9. The substrate processing system of claim 1, wherein the controller is configured to open and close the throttle valve at least partially in a pulsed manner.

10. The substrate processing system of claim 1, wherein the controller is configured to open and close the throttle valve at least partially at different speeds and at least partially in a pulsed manner.

11. The substrate processing system of claim 1 , further comprising: a gas delivery system configured to supply an inert gas to the processing chamber during the ALD process.

12. The substrate processing system of claim 1, further comprising: a gas delivery system configured to supply the precursor to the showerhead during the dosing step and to supply the purge gas during the purge step.

13. The substrate processing system of claim 1, further comprising a plasma generator disposed outside the processing chamber, wherein the plasma generator is configured to generate plasma and supply the plasma to the processing chamber through the showerhead during the ALD process.

14. The substrate processing system of claim 1, wherein the controller is configured to activate the vacuum pump during the ALD process.

15. A method of processing a substrate, the substrate being disposed on a susceptor in a substrate processing system, the method comprising: supplying a precursor during a dosing step of an atomic layer deposition (ALD) process and supplying a purge gas during a purge step of the ALD process to a showerhead disposed in the substrate processing system to process the substrate, wherein the dosing step and the purge step include a sequence in which a dosing step is followed by a subsequent purge step; During the purge step, opening a throttle valve connected to the process chamber and a vacuum pump; and The throttle valve is closed during at least a portion of the dosing step to increase the pressure within the processing chamber during the at least a portion of the dosing step of the ALD process.

16. The method of claim 15, wherein in the sequence, closing the throttle valve during the at least a portion of the dosing step comprises closing the throttle valve after initiating the dosing step and before initiating the subsequent purging step, the method further comprising: Opening the throttle valve at the end of the batching step; maintaining said throttle valve open throughout said subsequent purging step and until after initiation of a subsequent dosing step; and After starting the subsequent metering step, the throttle valve is closed.

17. The method of claim 15, wherein in the sequence, closing the throttle valve during the at least a portion of the dosing step comprises closing the throttle valve during the entirety of the dosing step, the method further comprising opening the throttle valve during the entirety of the subsequent purging step.

18. The method of claim 15, wherein in the sequence, closing the throttle valve during the at least a portion of the dosing step comprises closing the throttle valve from the beginning to the end of the dosing step, the method further comprising opening the throttle valve from the beginning to the end of the subsequent purging step.

19. The method of claim 15, wherein in the sequence, closing the throttle valve during the at least a portion of the batching step comprises closing the throttle valve for a predetermined time period at the end of the batching step, the method further comprising: opening the throttle valve at the end of the predetermined time period and before the subsequent purge step begins; maintaining said throttle valve open during said subsequent purging step until the subsequent dosing step is complete; and At the end of the subsequent metering step the throttle valve is closed.

20. The method of claim 15, wherein in the sequence, closing the throttle valve during the at least a portion of the batching step comprises closing the throttle valve for a predetermined time period before the end of the batching step, the method further comprising: opening the throttle valve at the end of the predetermined time period and before the subsequent purge step begins; maintaining the throttle valve open during the subsequent purging step until before the end of the subsequent dosing step; and The throttle valve is closed before the subsequent metering step is completed.

21. The method of claim 15, further comprising controlling a speed at which the throttle valve opens and closes.

22. The method of claim 15, further comprising at least partially opening and closing the throttle valve at different speeds.

23. The method of claim 15, further comprising at least partially pulsing the throttle valve open and close.

24. The method of claim 15, further comprising opening and closing the throttle valve at least partially at different speeds and at least partially in a pulsed manner.

25. The method of claim 15, further comprising supplying an inert gas to the processing chamber during the ALD process.

26. The method of claim 15, further comprising generating a plasma remotely from the processing chamber and supplying the plasma to the processing chamber through the showerhead during the ALD process.

27. The method of claim 15, further comprising activating the vacuum pump during the ALD process.

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