Low temperature atmospheric epitaxy process

Abstract

An epitaxial deposition method is disclosed. The method includes plasma pre-cleaning a substrate having an opening with an aspect ratio greater than 5:1. The plasma pre-cleaning is performed at a pre-cleaning pressure less than 5 Torr. The method also includes depositing a material in the opening using epitaxial deposition at a deposition pressure of about 700 Torr to about 800 Torr after the plasma pre-cleaning. In another embodiment, a gap fill method using epitaxial deposition includes patterning a substrate having an opening with an aspect ratio of 5:1. The method also includes plasma pre-cleaning the substrate, the plasma pre-cleaning being performed at a pre-cleaning pressure of about 1 Torr to about 5 Torr. The method also includes depositing a gap fill material in the opening using epitaxial deposition at a deposition pressure of about 700 Torr to about 800 Torr after the plasma pre-cleaning.

Description

Technical Field

[0001] The embodiments described herein generally relate to the fabrication of semiconductor devices. More specifically, embodiments of this disclosure relate to methods of epitaxial deposition. Background Technology

[0002] In integrated circuit manufacturing, high-temperature baking (above 1100°C) is typically used to remove native oxides before epitaxial deposition. However, high-temperature baking can cause problems such as dopant diffusion and silicon migration. Furthermore, high-temperature baking can damage the hard mold of the patterned substrate, potentially preventing the implementation of selective atmosphere epitaxy (SITE).

[0003] To overcome these drawbacks, low-pressure epitaxial deposition has been implemented. However, due to the low growth rate of the deposited film, low-pressure epitaxial deposition may result in low yields in manufacturing environments.

[0004] Therefore, there is a need for more efficient epitaxial deposition methods with control over dopant diffusion and silicon migration. Summary of the Invention

[0005] Embodiments of this disclosure provide an epitaxial deposition method. The method includes plasma pre-cleaning of a substrate having openings with an aspect ratio greater than 5:1. The plasma pre-cleaning is performed at a pre-cleaning pressure of less than 5 Torr. The method also includes, after plasma pre-cleaning, depositing material in the openings using epitaxial deposition at a deposition pressure of about 700 to about 800 Torr.

[0006] Embodiments of this disclosure provide a gap-filling method using epitaxial deposition. The method using epitaxial deposition includes patterning a substrate having openings with an aspect ratio of 5:1. The method also includes plasma pre-cleaning of the substrate, performed at a pre-cleaning pressure of about 1 to about 5 Torr. The method further includes, after plasma pre-cleaning, depositing a gap-filling material in the openings using epitaxial deposition at a deposition pressure of about 700 to about 800 Torr.

[0007] Embodiments of this disclosure provide a processing system. The processing system includes one or more processing chambers and a system controller configured to perform a method within the one or more processing chambers. The method includes plasma pre-cleaning of a substrate having an opening with an aspect ratio greater than 5:1. The plasma pre-cleaning is performed at a pre-cleaning pressure of about 1 to about 5 Torr. The method also includes, after plasma pre-cleaning, depositing material in the middle of the structure using epitaxial deposition at a deposition pressure of about 700 to about 800 Torr. Attached Figure Description

[0008] To gain a more detailed understanding of the features described above in the embodiments of this disclosure, a more specific description of the disclosure, which has been briefly outlined above, can be obtained with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of this disclosure and should not be construed as limiting its scope, as other equally effective embodiments are permissible.

[0009] Figure 1 A schematic top view of a multi-chamber processing system according to an embodiment of the present disclosure is shown.

[0010] Figure 2 According to one embodiment, from Figure 1 A cross-sectional view of the pre-cleaning system of a multi-chamber treatment system.

[0011] Figure 3 A method for low-temperature epitaxial deposition according to an embodiment of this disclosure is illustrated.

[0012] Figure 4 A method for low-temperature gap filling using epitaxial deposition, according to an embodiment of this disclosure, is illustrated.

[0013] Figure 5 This is a cross-sectional view of a substrate having a structure 507 disposed thereon, according to an embodiment.

[0014] For ease of understanding, the same reference numerals have been used to denote common elements in the figures where possible. It is contemplated that elements and features of one embodiment may be advantageously incorporated into other embodiments without further description. It is contemplated that elements disclosed in some embodiments may be advantageously utilized in other embodiments without further detail. Detailed Implementation

[0015] The embodiments described herein generally relate to the fabrication of semiconductor devices. More specifically, embodiments of this disclosure relate to methods for epitaxial deposition.

[0016] Figure 1This is a schematic top view of a multi-chamber processing system 100 according to one or more embodiments of this disclosure. The multi-chamber processing system 100 typically includes a factory interface 102, load-locking chambers 104, 106, transfer chambers 108, 110 with corresponding transfer robots 112, 114, holding chambers 116, 118, and processing chambers 120, 122, 124, 126, 128, 130. As detailed herein, substrates in the multi-chamber processing system 100 can be processed in various chambers and transferred between chambers without exposing the substrates to the surrounding environment outside the processing system 100. For example, substrates can be processed in various chambers and transferred between chambers maintained in a low-pressure (e.g., less than or equal to about 300 Torr) or vacuum environment without disrupting the low-pressure or vacuum environment between various processes performed on the substrates in the processing system 100. Therefore, the multi-chamber processing system 100 can provide an integrated solution for some substrate processing needs.

[0017] exist Figure 1 In the illustrated example, the factory interface 102 includes a docking station 132 and a factory interface robot 134 to facilitate substrate transfer. The docking station 132 is adapted to accept one or more front-opening unified pods (FOUPs) 136. In some examples, each factory interface robot 134 typically includes a blade 138 disposed at one end of the respective factory interface robot 134, which is adapted to transfer substrates from the factory interface 102 to load-locking chambers 104, 106.

[0018] Load-locking chambers 104 and 106 have corresponding ports 140 and 142 coupled to factory interface 102 and corresponding ports 144 and 146 coupled to transfer chamber 108. Transfer chamber 108 further has corresponding ports 148 and 150 coupled to holding chambers 116 and 118 and corresponding ports 152 and 154 coupled to processing chambers 120 and 122. Similarly, transfer chamber 110 has corresponding ports 156 and 158 coupled to holding chambers 116 and 118 and corresponding ports 160, 162, 164, and 166 coupled to processing chambers 124, 126, 128, and 130. For example, ports 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, and 166 may be slit valve openings with slit valves for allowing substrates to pass through via transfer robots 112 and 114 and providing a seal between the respective chambers to prevent gas from passing between them. Typically, any port is open for transferring the substrate through it. In other cases, the ports are closed.

[0019] Load locking chambers 104 and 106, transfer chambers 108 and 110, holding chambers 116 and 118, and processing chambers 120, 122, 124, 126, 128, and 130 are fluidly coupled to a gas and pressure control system. The gas and pressure control system may include one or more gas pumps (e.g., turbopumps, cryogenic pumps, low-vacuum pumps), gas sources, various valves, and conduits fluidly coupled to the various chambers. In operation, the factory interface robot 134 transfers a substrate from FOUP 136 to load locking chambers 104 or 106 via ports 140 or 142. The gas and pressure control system then evacuates load locking chambers 104 or 106. The gas and pressure control system further maintains a low-pressure or vacuum environment (which may include an inert gas) inside transfer chambers 108 and 110 and holding chambers 116 and 118. Therefore, evacuating the load-locking chambers 104 or 106 facilitates the transfer of substrates between the atmospheric environment of the factory interface 102 and the low-pressure or vacuum environment of the transfer chamber 108.

[0020] With the substrate in the de-evacuated load-locking chamber 104 or 106, the transfer robot 112 transfers the substrate from the load-locking chamber 104 or 106 to the transfer chamber 108 via port 144 or 146. Then, the transfer robot 112 can transfer the substrate to any one of the processing chambers 120 or 122 and / or transfer the substrate between the processing chambers 120 or 122 for processing via corresponding ports 152 and 154, and transfer the substrate to any one of the holding chambers 116 or 118 and / or transfer the substrate between the holding chambers 116 or 118 for holding pending further transfer via corresponding ports 148 and 150. Similarly, the transfer robot 114 can pick up substrates from holding chambers 116 or 118 via ports 156 or 158, and can transfer substrates to any one of processing chambers 124, 126, 128, 130 and / or transfer substrates between processing chambers 124, 126, 128, 130 for processing via corresponding ports 160, 162, 164, 166, and transfer substrates to any one of holding chambers 116, 118 and / or transfer substrates between holding chambers 116, 118 for holding pending further transfer via corresponding ports 156, 158. The transfer and holding of substrates within and between the various chambers can be conducted in a low-pressure or vacuum environment provided by the gas and pressure control system.

[0021] Processing chambers 120, 122, 124, 126, 128, and 130 may be any suitable chamber for processing the substrate. In some instances, processing chamber 120 may be capable of performing an etching process, processing chamber 122 may be capable of performing a cleaning process, and processing chambers 124, 126, 128, and 130 may be capable of performing a corresponding deposition process.

[0022] System controller 168 is coupled to multi-chamber processing system 100 for controlling multi-chamber processing system 100 or its components. For example, system controller 168 may control the operation of multi-chamber processing system 100 by directly controlling chambers 104, 106, 108, 110, 116, 118, 120, 122, 124, 126, 128, and 130, or by controlling controllers associated with chambers 104, 106, 108, 110, 116, 118, 120, 122, 124, 126, 128, and 130. In operation, system controller 168 collects and feeds back data from the respective chambers to coordinate the performance of processing system 100.

[0023] System controller 168 typically includes a central processing unit (CPU) 170, memory 172, and support circuitry 174. CPU 170 can be one of any type of general-purpose processor that can be used in an industrial environment. Memory 172 or a non-transitory computer-readable medium is accessible by CPU 170 and can be one or more of random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of local or remote digital storage. Support circuitry 174 is coupled to CPU 170 and may include cache, clock circuitry, input / output subsystems, power supplies, and the like. Computer instruction code stored in memory 172 (or in the memory of a specific processing chamber) as, for example, a commonly used software program is executed by CPU 170, typically implementing various methods disclosed herein under the control of CPU 170. When CPU 170 executes the computer instruction code, CPU 170 controls the chamber to perform processes according to various methods.

[0024] Other processing systems may be configured differently. For example, more or fewer processing chambers may be coupled to a transport device. In the illustrated example, the transport device includes transport chambers 108, 110 and holding chambers 116, 118. In other examples, more or fewer transport chambers (e.g., one transport chamber) and / or more or fewer holding chambers (e.g., no holding chambers) may be implemented as transport devices in a processing system.

[0025] Figure 2This is a cross-sectional view of the pre-cleaning system 200. The pre-cleaning system 200 may be one or more of the processing chambers 120, 122, 124, 126, 128, and 130. The pre-cleaning system 200 includes a pre-cleaning chamber 201 (also referred to as a process chamber). The pre-cleaning chamber 201 includes a chamber body 210. The chamber body 210 includes a bottom 211, a cover assembly 214, and one or more chamber walls 212 connecting the bottom 211 and the cover assembly 214. The chamber body 210 can enclose the internal volume 205 of the pre-cleaning chamber 201.

[0026] The pre-cleaning chamber 201 further includes a substrate support assembly 216. The substrate support assembly 216 may include a substrate support 232, an actuator 234, and a shaft 236 connecting the actuator 234 and the substrate support 232. The substrate support 232 may be located in the internal volume 205 to support the substrate 50 during processing.

[0027] The chamber body 210 may further include a slit valve 215 to allow insertion of the substrate 50 into and removal of the substrate 50 from the internal volume 205 of the pre-cleaning chamber 201. The pre-cleaning system 200 and the multi-chamber processing system 100 may be configured to maintain a pressure in the internal volume 205 lower than the pressure in the transfer chamber 108 when the slit valve 215 is open, to prevent gas and / or particles from flowing from the pre-cleaning chamber 201 into the transfer chamber 108, as described in further detail below.

[0028] A cover assembly 214 is disposed at the upper end of the chamber body 210. The cover assembly 214 may include a remote plasma source 220 for generating plasma from a cleaning gas supplied to the remote plasma source 220. Cleaning gas may be supplied from a cleaning gas source 227 through a gas inlet 226 of the pre-cleaned chamber 201. The cleaning gas source 227 may include separate containers for each cleaning gas. In one embodiment, the cleaning gas from the cleaning gas source 227 may include one or more of hydrogen (H2), nitrogen trifluoride (NF3), and ammonia (NH3). The remote plasma source 220 may include a first electrode 221 and a second electrode 222. The first electrode 221 may be spaced apart from the second electrode 222. The remote plasma source 220 may include a plasma generating volume 229 positioned between the first electrode 221 and the second electrode 222.

[0029] The pre-cleaning system 200 may include a radio frequency (RF) power supply 224. The RF power supply 224 may be connected to a first electrode 221. A second electrode 222 may be connected to electrical ground to serve as a return path for the RF power when plasma is generated in the volume 229. The RF power supply 224 can be used to generate plasma containing the clean gas within the plasma generation volume 229 when clean gas is supplied to a remote plasma source 220.

[0030] The cover assembly 214 may further include a partition 228 and a nozzle 230 for distributing gas and / or plasma to the internal volume 205 of the pre-cleaning chamber 201. The partition 228 may be positioned between the remote plasma source 220 and the nozzle 230. The partition 228 may receive plasma and / or gas discharged from the remote plasma source 220. In some embodiments, one or more gases may be supplied directly to the partition 228 or the nozzle 230, thereby allowing bypassing the remote plasma source 220.

[0031] The pre-cleaning system 200 may further include an inert gas source 240 connected to the pre-cleaning chamber 201. In one embodiment, the inert gas source 240 includes nitrogen, but other inert gases (e.g., argon) may also be used. The inert gas can be used to pressurize the internal volume 205 of the pre-cleaning chamber 201 after performing a pre-cleaning process on the substrate 50 and / or before transferring a new substrate 50 to the pre-cleaning chamber 201. The pre-cleaning system 200 may include a pressure sensor 260 configured to measure the pressure of the internal volume 205 of the pre-cleaning chamber 201.

[0032] An inert gas source 240 can be connected to the gas inlet 226 of the process chamber via a first supply line 245 or a second supply line 246 of the pre-cleaning system 200. The first supply line 245 and the second supply line 246 can be connected to the gas inlet 226 via a common supply line 247. The first supply line 245 and the second supply line 246 can be arranged to form parallel (i.e., alternative) paths relative to each other, such that gas can be supplied to the pre-cleaning chamber 201 via one of the supply lines without passing through the other.

[0033] The first supply line 245 may include a first supply valve 241, which can be opened to connect the first supply line 245 with a common supply line 247. The second supply line 246 may include a second supply valve 242, which can be opened to connect the second supply line 246 with the common supply line 247.

[0034] The first supply line 245 may have a smaller inner diameter than the second supply line 246. In some embodiments, the inner diameter of the first supply line 245 may be from about 5% to about 90% of the inner diameter of the second supply line 246, such as from about 10% to about 50%. The smaller diameter of the first supply line 245 can be used to slowly increase the pressure in the internal volume 205 from the vacuum pressure used for the pre-cleaning process (e.g., 2 to 20 Torr, such as between about 3 and 5 Torr) after a pre-cleaning process is performed on the substrate 50. On the other hand, the second supply line 246 can be used to rapidly increase the pressure in the internal volume 205 back to atmospheric pressure or near atmospheric pressure after the pressure reaches a higher pressure (e.g., 300 Torr) through the gas supplied from the smaller first supply line 245. Slowly increasing the pressure after the pre-cleaning process prevents the possibility of damage to the substrate 50 due to sudden pressure changes, such as mechanical damage caused by shaking or otherwise unintentionally moving the substrate 50.

[0035] Using different supply lines with different inner diameters is one way to vary the rate at which gas is supplied to the internal volume 205. In other embodiments, slower pressure changes can be achieved, for example, by an analog control valve on a single supply line. In some of these other embodiments, sensors (such as flow meters or pressure sensors) can be used to control the analog control valve or other actuators (e.g., variable speed pumps) to control the rate at which pressure increases in the internal volume 205 when inert gas is supplied to it, thus enabling slower pressure changes in the internal volume 205.

[0036] The pre-cleaning system 200 may further include a vacuum pump 218 configured to discharge gas from the pre-cleaning chamber 201 through a discharge port 223. The vacuum pump 218 may be connected to the discharge port 223 via a first discharge line 261 or a second discharge line 262 of the pre-cleaning system 200. The first discharge line 261 and the second discharge line 262 may be arranged to form parallel (i.e., alternative) paths relative to each other, such that gas can be discharged from the pre-cleaning chamber 201 through one of the discharge lines without passing through the other. The first discharge line 261 and the second discharge line 262 may be connected to the discharge port 223 via a common discharge line 263. The first discharge line 261 may include a first discharge valve 219, which may open to fluidly couple the first discharge line 261 to the common discharge line 263. The second discharge line 262 may include a second discharge valve 239, which can be opened to fluidly couple the second discharge line 262 to the common discharge line 263.

[0037] The first discharge line 261 may have a smaller inner diameter than the second discharge line 262. All references to inner diameter provided in this disclosure also apply to internal cross-sectional areas, for example, when a component (e.g., a fluid conduit) has a non-circular cross-section. In some embodiments, the inner diameter of the first discharge line 261 may be from about 5% to about 75% of the inner diameter of the second discharge line 262, such as from about 10% to about 50%. The smaller diameter of the first discharge line 261 can be used to smoothly and slowly reduce the pressure in the internal volume 205 from atmospheric pressure or near atmospheric pressure (e.g., 700 to 800 Torr) to a lower pressure, such as from about 400 Torr to 650 Torr, such as about 600 Torr. The pressure reduction may be performed, for example, after the substrate 50 has been transferred from the transfer chamber 108 to the pre-cleaning chamber 201, which is maintained at atmospheric pressure or near atmospheric pressure. On the other hand, the second discharge line 262 can be used to rapidly reduce the pressure in the internal volume 205 to near the pressure used for the pre-cleaning plasma process, such as less than 50 Torr, such as about 100 to about 20 Torr, such as between about 300 to about 5 Torr. Slowly reducing the pressure after the substrate 50 is transferred to the pre-cleaning chamber 201 prevents the possibility of damage to the substrate 50 due to sudden pressure changes, such as mechanical damage caused by shaking or otherwise unintentionally moving the substrate 50.

[0038] Using different discharge lines with different inner diameters is one way to change the rate at which gas and / or plasma is discharged from the internal volume 205, thus enabling slower pressure changes within the internal volume 205. In other embodiments, slower pressure changes can be achieved, for example, via an analog control valve on a single discharge line. In some of these other embodiments, sensors (such as flow meters or pressure sensors) can be used to control the analog control valve or other actuators (e.g., variable-speed vacuum pumps) to control the rate at which the pressure in the internal volume 205 decreases as it drops to the vacuum pressure used to perform the plasma pre-cleaning process.

[0039] As described above, the substrate support assembly 216 includes a substrate support 232, an actuator 234, and a shaft 236 connecting the actuator 234 and the substrate support 232. The shaft 236 extends through a centrally located opening formed in the bottom 211 of the chamber body 210. The actuator 234 is flexibly sealed to the bottom 211 of the chamber body 210 by a bellows (not shown) that prevents vacuum leakage from around the shaft 236. The actuator 234 allows the substrate support 232 to move vertically within the chamber body 210 between a process position and a lower transfer position. The transfer position may be slightly below the opening of a slit valve 215 formed through one or more walls 212 of the chamber body 210.

[0040] Although not shown, in some embodiments, RF and / or DC biasers may be coupled to substrate support 232 to assist in directing clean plasma toward substrate 50.

[0041] The pre-cleaning system 200 may further include an auxiliary discharge assembly 270. The auxiliary discharge assembly 270 may include a first auxiliary discharge line 275, a second auxiliary discharge line 276, and a common auxiliary discharge line 278. The auxiliary discharge assembly 270 may further include a vacuum pump or other means for creating a negative pressure in the auxiliary discharge assembly 270 lines relative to the internal volume 205 of the pre-cleaning chamber 201, such that when the valve of the auxiliary discharge assembly 270 is opened, gas is discharged through the auxiliary discharge assembly 270 from the internal volume 205.

[0042] A common auxiliary discharge line 278 can be connected to the internal volume 205 of the pre-cleaning chamber 201. A first auxiliary discharge line 275 and a second auxiliary discharge line 276 can be connected to the internal volume 205 of the pre-cleaning chamber 201 via the common auxiliary discharge line 278. The first auxiliary discharge line 275 may include a first auxiliary discharge valve 272, which is openable to connect the first auxiliary discharge line 275 to the common auxiliary discharge line 278. The second auxiliary discharge line 276 may include a second auxiliary discharge valve 274, which is openable to connect the second auxiliary discharge line 276 to the common auxiliary discharge line 278.

[0043] In the event of a high-pressure condition, the first auxiliary vent valve 272 may be opened. The first auxiliary vent line 275 may include a pressure sensor 271 to measure the pressure inside the first auxiliary vent line 275. When the measured pressure exceeds a given threshold (e.g., 800 Torr), the first auxiliary vent valve 272 may open to relieve pressure within the internal volume 205. Because the pre-cleaning chamber 201 operates at a higher pressure than other pre-cleaning chambers that typically operate at vacuum pressures (e.g., below 100 Torr) used for pre-cleaning processes and substrate transfer, more components of the pre-cleaning chamber are secured to each other or otherwise fastened. For example, components of the cover assembly 214 may be fastened to other components in the cover assembly 214 and / or to the chamber wall 212. For pre-cleaning chambers operating at vacuum pressures used for pre-cleaning processes and for transferring substrates to or from the pre-cleaning chamber, some of these components in the cover assembly are typically not secured. Additional securing of components in the pre-cleaning chamber 201 helps prevent any component from moving during pressure changes that occur during each substrate pre-cleaning and transfer, as described in further detail below. However, securing these components may pose safety concerns, as previously unsecured components may move to alleviate high-pressure conditions. In the pre-cleaning chamber 201, a first auxiliary vent valve 272 can open to alleviate a high-pressure condition when the pressure sensor 271 measures it, preventing unsafe high-pressure conditions from occurring.

[0044] The second auxiliary vent valve 274 can be opened when the slit valve 215 is open, allowing gas to flow from the internal volume 205 and out of the auxiliary vent assembly 270. The internal volume 205 of the pre-cleaning chamber 201 is generally considered less clean than the internal volume of the transfer chamber 108. Therefore, gas should not flow from the internal volume 205 of the pre-cleaning chamber 201 to the internal volume of the transfer chamber 108. Opening the second auxiliary vent valve 274 when the slit valve 215 is open reduces the pressure in the internal volume 205 relative to the pressure in the internal volume of the transfer chamber 108, and gas flows from the internal volume of the transfer chamber 108 through the internal volume 205 of the pre-cleaning chamber 201 and out through the auxiliary vent assembly 270.

[0045] The pre-cleaning system 200 may also include a controller 290 for controlling the pre-cleaning system 200. Figure 2 ) and processing system 100 ( Figure 1The process within other parts of the device. Controller 290 can be any type of controller used in an industrial environment, such as a programmable logic controller (PLC). Controller 290 includes a processor 292, memory 294, and input / output (I / O) circuitry 296. Controller 290 may further include one or more of the following components (not shown), such as one or more power supplies, a clock, communication components (e.g., a network interface card), and a user interface typically found in controllers of semiconductor devices.

[0046] Memory 294 may include non-transitory memory. Non-transitory memory may be used to store programs and settings as described below. Memory 294 may include one or more readily available types of memory, such as read-only memory (ROM) (e.g., electrically erasable programmable read-only memory; EEPROM), flash memory, floppy disk, hard disk, or random access memory (RAM) (e.g., non-volatile random access memory; NVRAM).

[0047] Processor 292 is configured to execute various programs stored in memory 294, such as those configured to execute (see below). Figure 3 The procedure of method 1000. During the execution of these procedures, controller 290 may communicate with I / O devices (e.g., sensors and actuators) via I / O circuitry 296. For example, during the execution of these procedures and communication via I / O circuitry, controller 290 may control outputs (e.g., opening and closing valves) and receive information from feedback devices (e.g., feedback regarding the open / closed state of valves), sensors, and other instruments in pre-cleaning system 200 and other parts of multi-chamber processing system 100.

[0048] The memory 294 may further include various operational settings for controlling the pre-cleaning system 200 and other parts of the multi-chamber treatment system 100. For example, among various other settings, these settings may include those for transitions between slow changes in pressure within the internal volume 205 and faster changes in pressure within the internal volume 205 (see below). Figure 3 The pressure setting in the method 1000.

[0049] Figure 3This is a method 300 for low-temperature epitaxial deposition. At operation 301, a substrate is placed in a fab interface 102. The fab interface 102 includes a docking station 132 and a fab interface robot 134 to facilitate substrate transfer. The docking station 132 is adapted to accept one or more front-opening wafer transfer cassettes (FOUPs) 136.

[0050] At operation 302, the substrate is transferred from the factory interface 102 to the load locking chambers 104, 106. In some instances, each factory interface robot 134 typically includes a blade 138 disposed at one end of the respective factory interface robot 134, which is adapted to transfer the substrate from the factory interface 102 to the load locking chambers 104, 106. The load locking chambers 104, 106 have corresponding ports 140, 142 coupled to the factory interface 102 and corresponding ports 144, 146 coupled to the transfer chamber 108.

[0051] At operation 303, the substrate is transferred from the load locking chambers 104, 106 to the transfer chamber 108. The transfer chamber 108 has corresponding ports 148, 150 coupled to the holding chambers 116, 118 and corresponding ports 152, 154 coupled to the processing chambers 120, 122.

[0052] At operation 304, the substrate is transferred from transfer chamber 108 to processing chambers 120 and 122. Transfer chamber 108 has a pressure of about 700 to about 800 Torr, such as about 760 Torr.

[0053] At operation 305, the substrate undergoes plasma pre-cleaning in processing chambers 120 and 122. The pre-cleaning process includes the removal of native oxide from the substrate. The plasma pre-cleaning is performed at a temperature of approximately 100°C to approximately 300°C, such as approximately 150°C to approximately 250°C, such as approximately 200°C. The plasma pre-cleaning is performed at a pressure of approximately 1 Torr to approximately 5 Torr, such as approximately 3 Torr. The plasma pre-cleaning process lasts approximately 15 seconds to approximately 45 seconds, such as approximately 30 seconds.

[0054] At operation 306, the substrate is transferred from processing chambers 120 and 122 to transfer chamber 110. The substrate is transferred to transfer chamber 110 via holding chambers 116 and 118. Transfer chamber 110 has corresponding ports 156 and 158 coupled to holding chambers 116 and 118 and corresponding ports 160, 162, 164, and 166 coupled to processing chambers 124, 126, 128, and 130.

[0055] At operation 307, the substrate is transferred from the transfer chamber to processing chambers 124, 126, 128, and 130. The transfer chamber 108 has a pressure of approximately 700 to approximately 800 Torr, such as approximately 760 Torr.

[0056] At operation 308, a film is deposited on the substrate by epitaxial deposition. In some embodiments, the epitaxial deposition is interstitial deposition, wherein a film (e.g., a deposition material) is deposited between multiple structures disposed on the surface of the substrate. These structures have a high aspect ratio greater than 5:1, such as greater than 10:1. Epitaxial deposition includes depositing the film at a temperature of about 400°C to about 1200°C, such as about 800°C to about 1000°C, such as about 950°C. A precursor gas is used to deposit the film. The precursor gas may include silicon precursors, such as trichlorosilane (SiHCl3) and dichlorosilane (DCS). Epitaxial deposition is performed at a pressure of about 700 Torr to about 800 Torr, such as about 760 Torr. The epitaxial deposition takes about 15 seconds to about 45 seconds (such as about 30 seconds), or about 100 seconds to about 5000 seconds, such as about 500 seconds to about 1000 seconds, such as about 700 seconds.

[0057] Atmospheric pressure (ATM) low-temperature epitaxial deposition improves dopant diffusion control, for example, reducing dopant diffusion into the deposited film. Pre-cleaning the substrate before low-temperature epitaxial deposition removes the native oxide layer from the substrate. Therefore, the removal of the native oxide layer enables low-temperature epitaxial deposition. Furthermore, compared to low-pressure epitaxial deposition, low-temperature atmospheric epitaxial deposition increases yield in the manufacturing environment. During epitaxial deposition, yield is increased through increased epitaxial growth. Additionally, low-temperature epitaxial deposition enables selective epitaxial deposition.

[0058] Figure 4 A method 400 for low-temperature gap filling using epitaxial deposition is described. At operation 401, a substrate is placed in a fab interface 102. The fab interface 102 includes a docking station 132 and a fab interface robot 134 to facilitate substrate transfer. The docking station 132 is adapted to accept one or more front-opening wafer transfer cassettes (FOUPs) 136.

[0059] At operation 402, the substrate is transferred from the factory interface 102 to the load locking chambers 104, 106. In some instances, each factory interface robot 134 typically includes a blade 138 disposed at one end of the respective factory interface robot 134, which is adapted to transfer the substrate from the factory interface 102 to the load locking chambers 104, 106. The load locking chambers 104, 106 have corresponding ports 140, 142 coupled to the factory interface 102 and corresponding ports 144, 146 coupled to the transfer chamber 108.

[0060] At operation 403, the substrate is transferred from the load locking chambers 104, 106 to the transfer chamber 108. The transfer chamber 108 has corresponding ports 148, 150 coupled to the holding chambers 116, 118 and corresponding ports 152, 154 coupled to the processing chambers 120, 122.

[0061] At operation 404, the substrate is transferred from transfer chamber 108 to processing chambers 120, 122. Transfer chamber 108 has a pressure of about 700 to about 800 Torr, such as about 760 Torr.

[0062] At operation 405, the substrate is patterned in processing chambers 120 and 122. The substrate is patterned to form a high aspect ratio structure, such as a structure having an aspect ratio greater than about 5:1 (e.g., greater than about 10:1). In some embodiments, a lithographic printing process can be used to pattern the substrate to form multiple structures. In other embodiments, a deposition process can be used to pattern the substrate to form multiple structures. The deposition process may include atomic layer deposition (ALD), chemical vapor deposition (CVD), or physical vapor deposition (PVD).

[0063] At operation 406, the substrate undergoes plasma pre-cleaning in processing chambers 120 and 122. In some embodiments, the substrate is transferred to another of processing chambers 120 and 122. In other embodiments, the substrate undergoes plasma pre-cleaning in the same processing chambers 120 and 122 as the patterning chamber. The pre-cleaning process includes removing native oxide from the substrate. The plasma pre-cleaning is performed at a temperature of about 100°C to about 300°C, such as about 150°C to about 250°C, such as about 200°C. The plasma pre-cleaning is performed at a pressure of about 1 Torr to about 5 Torr, such as about 3 Torr. The plasma pre-cleaning lasts for about 15 seconds to about 45 seconds, such as about 30 seconds.

[0064] At operation 407, the substrate is transferred from processing chambers 120 and 122 to transfer chamber 110. The substrate is transferred to transfer chamber 110 via holding chambers 116 and 118. Transfer chamber 110 has corresponding ports 156 and 158 coupled to holding chambers 116 and 118 and corresponding ports 160, 162, 164, and 166 coupled to processing chambers 124, 126, 128, and 130.

[0065] At operation 408, the substrate is transferred from the transfer chamber to processing chambers 124, 126, 128, and 130. The transfer chamber 108 has a pressure of approximately 700 to approximately 800 Torr, such as approximately 760 Torr.

[0066] At operation 409, interstitial material is deposited on the substrate via epitaxial deposition. The interstitial material is deposited between structures formed on the substrate. Epitaxial deposition involves depositing the interstitial material at temperatures ranging from about 400°C to about 1200°C, such as from about 800°C to about 1000°C, such as about 950°C. The interstitial material is deposited using a precursor gas. Precursor gases include silicon precursors, such as SiHCl3 and DCS. The flow rate of the precursor gas can vary depending on the precursor gas used. For example, the flow rate of SiHCl3 can be from about 10 standard liters per minute (SLM) to about 20 SLM, such as about 15 SLM. In another example, the flow rate of DCS can be from about 400 standard cubic centimeters per minute (SCcm) to about 1000 SCcm. Epitaxial deposition is performed at pressures ranging from about 700 Torr to about 800 Torr, such as about 760 Torr. The epitaxial deposition process takes approximately 100 seconds to 5000 seconds, such as approximately 500 seconds to 1000 seconds, such as approximately 700 seconds.

[0067] Compared to low-pressure epitaxial deposition, atmospheric pressure (ATM) low-temperature epitaxial deposition increases yield in the manufacturing environment. During epitaxial deposition, yield is increased by enhancing epitaxial growth. Furthermore, low-temperature epitaxial deposition enables selective epitaxial deposition, such as selective orientation of interstitial material deposition to form a porous substrate. Low-temperature epitaxial deposition allows for selective epitaxial deposition along gaps formed in the middle of the structure, while simultaneously reducing cross-structure deposition. This reduction in cross-structure deposition lowers the likelihood of interstitial material prematurely closing gaps in the middle of the structure, allowing more interstitial material to be deposited in the gaps between structures.

[0068] Figure 5This is a cross-sectional view of a substrate 50 having a structure 507 disposed thereon. The structure 507 defines an opening 508. The opening 508 is about 1.0 μm to about 1.3 μm wide, has a high aspect ratio (e.g., greater than about 5:1, such as greater than about 10:1), and the spacing between adjacent openings 508 is between about 50 nm and about 180 nm. During methods 300 and 400, material may be deposited on the structure 507 and in the openings 508 to fill the region in the middle of the structure 507. The structure 507 may include refractory metals such as tungsten (W), molybdenum (Mo), tantalum (Ta), titanium (Ti), hafnium (Hf), vanadium (V), chromium (Cr), manganese (Mn), ruthenium (Ru), alloys thereof, silicide compounds thereof, nitride compounds thereof, or combinations thereof. In other examples, structure 507 may be other metals, such as copper (Cu), nickel (Ni), cobalt (Co), iron (Fe), aluminum (Al), palladium (Pd), gold (Au), silver (Au), platinum (Pt), their alloys, their nitride compounds, or combinations thereof. In other embodiments, the structure may be silicon or silicon germanium (SiGe).

[0069] In summary, the above methods include low-temperature epitaxial deposition processes. Low-temperature atmospheric epitaxial deposition involves deposition temperatures of approximately 400°C to approximately 1200°C and deposition times of approximately 15 seconds to approximately 45 seconds. Low-temperature atmospheric epitaxial deposition overcomes the disadvantages of low-pressure deposition by increasing throughput in the manufacturing environment. Furthermore, low-temperature epitaxial deposition enables more efficient interstitial filling, selective epitaxial deposition, and improved dopant diffusion control.

[0070] Although the foregoing describes an embodiment of this disclosure, other and additional embodiments of this disclosure may be designed without departing from its basic scope, and the scope of such embodiments is defined by the foregoing claims.

Claims

1. An epitaxial deposition method, the method comprising: Plasma pre-cleaning is performed on substrates with openings having an aspect ratio greater than 5:1, wherein the plasma pre-cleaning is performed at a pre-cleaning pressure of less than 5 Torr; and Following plasma pre-cleaning, material is deposited in the opening using epitaxial deposition at a deposition pressure of approximately 700 to approximately 800 Torr.

2. The method of claim 1, further comprising: The substrate is placed in the factory interface; and The substrate is transferred from the factory interface to the processing chamber.

3. The method of claim 1, wherein: The plasma pre-cleaning occurs in the first processing chamber of the substrate processing system; and The epitaxial deposition occurs in the second processing chamber of the substrate processing system.

4. The method of claim 3, further comprising: The substrate is transferred from the first processing chamber to the second processing chamber.

5. The method of claim 4, wherein the transfer chamber between the first processing chamber and the second processing chamber has a pressure of about 700 Torr to about 800 Torr.

6. The method of claim 1, wherein: The plasma pre-cleaning includes a pre-cleaning temperature of approximately 100°C to approximately 300°C; The deposition of the material comprises a deposition temperature of about 400°C to about 1200°C; and The deposition of the material comprises a deposition time of approximately 100 seconds to approximately 5000 seconds.

7. A gap-filling method using epitaxial deposition, the method comprising: Pattern the substrate with an opening having a depth-to-width ratio of 5:1; The substrate is subjected to plasma pre-cleaning, wherein the plasma pre-cleaning is performed at a pre-cleaning pressure of approximately 1 to approximately 5 Torr; and Following plasma pre-cleaning, interstitial material is deposited in the opening using epitaxial deposition at a deposition pressure of approximately 700 to approximately 800 Torr.

8. The method of claim 7, further comprising: The substrate is placed in the factory interface; and The substrate is transferred from the factory interface to the processing chamber.

9. The method of claim 7, wherein: The patterning occurs in the first processing chamber of the substrate processing system; The plasma pre-cleaning occurs in the second processing chamber of the substrate processing system; and The epitaxial deposition occurs in the third processing chamber of the substrate processing system.

10. The method of claim 9, further comprising: The substrate is transferred from the first processing chamber to the second processing chamber; and The substrate is transferred from the second processing chamber to the third processing chamber.

11. The method of claim 10, wherein the transfer chamber between the first processing chamber, the second processing chamber and the third processing chamber has a pressure of about 700 Torr to about 800 Torr.

12. The method of claim 7, wherein: The plasma pre-cleaning includes a pre-cleaning temperature of approximately 100°C to approximately 300°C; The deposition of the material comprises a deposition temperature of about 400°C to about 1200°C; and The deposition of the material comprises a deposition time of approximately 100 seconds to approximately 5000 seconds.

13. A processing system, the processing system comprising: One or more processing chambers; and A system controller configured to enable the processing system to operate within one or more processing chambers: Plasma pre-cleaning is performed on substrates with openings having an aspect ratio greater than 5:1, wherein the plasma pre-cleaning is performed at a pre-cleaning pressure of approximately 1 to approximately 5 Torr; and Following plasma pre-cleaning, material is deposited in the middle of the structure using epitaxial deposition at a deposition pressure of approximately 700 to approximately 800 Torr.

14. The processing system of claim 13, wherein the plasma pre-cleaning comprises a pre-cleaning temperature of about 100°C to about 300°C.

15. The processing system of claim 13, further comprising conveying the substrate.

16. The processing system of claim 13, wherein: The plasma pre-cleaning occurs in the first processing chamber of the substrate processing system; and The epitaxial deposition occurs in the second processing chamber of the substrate processing system.

17. The processing system of claim 16, further comprising: The substrate is transferred from the first processing chamber to the second processing chamber.

18. The processing system of claim 17, wherein the transfer chamber between the first processing chamber and the second processing chamber has a pressure of about 700 Torr to about 800 Torr.

19. The processing system of claim 13, further comprising: Prior to plasma pre-cleaning, the substrate is patterned in the processing chamber.

20. The processing system of claim 19, further comprising: The patterning occurs in the first processing chamber; The substrate is transferred from the first processing chamber to the second processing chamber; The plasma pre-cleaning occurs in the second processing chamber; The substrate is transferred from the second processing chamber to the third processing chamber; and The epitaxial deposition occurs in the third processing chamber.

Images