Method for processing epitaxial semiconductor wafer

Abstract

A method of processing a semiconductor wafer includes placing a semiconductor wafer in a recess of a carrier within a heating chamber. The recess is defined in the carrier by a downwardly depending sidewall. The method also includes determining a distance of a peripheral edge of the wafer from the sidewall. The method also includes supplying a first process gas into the heating chamber at a first gas flow rate and a second process gas into the heating chamber at a second gas flow rate, and supplying heat to the heating chamber. The method also includes modulating the first gas flow rate, the second gas flow rate and / or the heat supplied to the heating chamber controls a deposition rate of the first process gas and the second process gas near the peripheral edge of the wafer based on the determined distance of the peripheral edge of the wafer from the sidewall.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 477,960, filed on December 30, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The field of the present disclosure relates generally to semiconductor wafer processing, and more particularly to modulating process conditions during epitaxial processing based on semiconductor wafer placement in a susceptor of an epitaxial chamber. Background Art

[0004] Epitaxial chemical vapor deposition (ECD) is a process that grows thin layers of material onto a semiconductor wafer, with the same lattice structure as the wafer itself. Using this process, layers with different conductivity types, dopants, or dopant concentrations can be applied to the semiconductor wafer to achieve the desired electrical properties.

[0005] Before epitaxial deposition, the semiconductor wafer is usually placed in a carrier in the deposition chamber of the reactor. The epitaxial deposition process is to introduce a clean gas into the front surface of the wafer to preheat and clean the front surface of the wafer. The clean gas removes the native oxide from the front surface to allow the epitaxial silicon layer to grow continuously and uniformly on the surface during the subsequent steps of the deposition process. The epitaxial deposition process continues by introducing a gaseous silicon source gas (such as trichlorosilane, SiHCl3) into the front surface of the wafer to deposit and grow an epitaxial layer of silicon on the front surface. The rear surface opposite to the front surface of the carrier can be subjected to hydrogen at the same time. During epitaxial deposition, the carrier supporting the semiconductor wafer in the deposition chamber rotates during the process to ensure that the epitaxial layer grows uniformly.

[0006] Recently, there has been an increasing demand for epitaxial semiconductor wafers with uniform thickness and flatness across the wafer, particularly for wafers used in complementary metal oxide semiconductor (CMOS) and integrated circuit device fabrication. Conventional systems and methods for epitaxial processing of semiconductor wafers remain limited in their ability to efficiently and / or consistently produce the desired thickness and flatness uniformity of deposited epitaxial layers. For example, conventional systems and methods may be unable to adequately compensate for various factors in the epitaxial deposition process that negatively impact the thickness of the deposited epitaxial layer near the peripheral edge of the wafer. As a result, edge roll-off may occur along the deposition surface of the wafer near the peripheral edge, which degrades the uniformity of the thickness and flatness of the epitaxial wafer.

[0007] What is needed are systems and methods that facilitate mitigating edge roll-off effects during epitaxial processing of semiconductor wafers to improve uniformity in thickness and flatness of epitaxial semiconductor wafers.

[0008] This background section is intended to introduce the reader to various aspects of the present technology that may be related to various aspects of the present disclosure described and / or claimed below. It is believed that this discussion will help provide the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Therefore, these statements should be read in this light and not as admissions of prior art. Summary of the Invention

[0009] One aspect is a method for processing a semiconductor wafer in a heating chamber including a carrier for supporting the semiconductor wafer. The carrier has a front surface and a recess in the front surface defined by downwardly depending sidewalls. The method includes placing a semiconductor wafer in the recess of the carrier and determining a distance between a peripheral edge of the wafer and the sidewalls. The method also includes supplying a first process gas into the heating chamber at a first gas flow rate in a first gas direction and supplying a second process gas into the heating chamber at a second gas flow rate in a second gas direction intersecting the first gas direction. The method also includes supplying heat to the heating chamber to induce deposition of the first and second process gases on a surface of the wafer. The method also includes modulating at least one of the first and second gas flow rates and the heat supplied to the heating chamber to control deposition rates of the first and second process gases near the peripheral edge of the wafer based on the determined distance between the peripheral edge of the wafer and the sidewalls.

[0010] Another aspect is a method for processing a semiconductor wafer in a heating chamber including a carrier for supporting the semiconductor wafer. The carrier has a front surface and a recess in the front surface defined by downwardly depending sidewalls. The method includes placing a semiconductor wafer in the recess of the carrier. The method also includes determining a peripheral edge region of the wafer located at a minimum distance from the sidewalls. The method also includes supplying a first process gas into the heating chamber at a first gas flow rate in a first gas direction and supplying a second process gas into the heating chamber at a second gas flow rate in a second gas direction intersecting the first gas direction. The method also includes modulating at least one of the first gas flow rate and the second gas flow rate to selectively increase the deposition rate of the first process gas and the second process gas near the peripheral edge region of the wafer located at the minimum distance from the sidewalls.

[0011] Another aspect is a method for processing a semiconductor wafer within a heating chamber comprising a carrier for supporting the semiconductor wafer. The carrier has a front surface and a recess in the front surface defined by downwardly depending sidewalls. The method includes placing a semiconductor wafer in the recess of the carrier. The method also includes determining a peripheral edge region of the wafer located at a minimum distance from the sidewalls. The method also includes supplying a process gas into the heating chamber and supplying heat to the heating chamber to induce deposition of the process gas on a surface of the wafer. The method also includes modulating the heat supplied to the heating chamber to selectively increase the deposition rate of the process gas near the peripheral edge region of the wafer located at the minimum distance from the sidewalls.

[0012] Various refinements exist with respect to the features described above. Further features may also be incorporated into the aspects described above. These refinements and additional features may exist individually or in any combination. For example, various features discussed below with respect to any of the described embodiments may be incorporated into any of the above-described aspects, individually or in any combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic cross-section of a heating chamber for processing semiconductor wafers.

[0014] Figure 2 yes Figure 1 Schematic cross section of a heating chamber of FIG. 1 , in which elements are omitted to show the semiconductor wafer supported on the carrier in more detail.

[0015] Figure 3 yes Figure 1 Schematic top view of a heating chamber of FIG. 1 , in which elements are omitted to show in more detail the semiconductor wafer supported on the carrier.

[0016] Figure 4 A process flow is an example method for processing semiconductor wafers.

[0017] Figure 5 is a graph illustrating modulating localized heating within a heating chamber based on the distance between a peripheral edge of a semiconductor wafer and a sidewall of a recess of a susceptor within the heating chamber.

[0018] Figure 6 It is a conceptual description of whether it can be used or not. Figure 5 Graph of the normalized edge roll-off of an epitaxial wafer processed with localized heating modulation as described in FIG.

[0019] Figure 7 is a graph illustrating modulation of the flow rate of a trichlorosilane process within a heating chamber based on the distance between the peripheral edge of a semiconductor wafer and the sidewall of a recess of a susceptor within the heating chamber.

[0020] Figure 8 It is a conceptual description of whether it can be used or not. Figure 7 Graph of the normalized edge roll-off of epitaxial wafers processed with trichlorosilane gas flow rate modulation as described in FIG.

[0021] Figure 9 is a graph illustrating modulation of the flow rate of a hydrochloric acid process within a heating chamber based on the distance between the peripheral edge of a semiconductor wafer and the sidewall of a recess of a susceptor within the heating chamber.

[0022] Figure 10 It is a conceptual description of whether it can be used or not. Figure 9 Graph of the normalized edge roll-off of epitaxial wafers processed with hydrochloric acid gas flow rate modulation as illustrated.

[0023] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0024] refer to Figure 1 , an example heating chamber 100 for use in accordance with the present disclosure is shown. Heating chamber 100 can be, for example, a processing reactor (e.g., a deposition or thermal treatment reactor, including a vapor phase epitaxial processing reactor) for processing semiconductor wafers. Heating chamber 100 is an example and, unless otherwise specified, any reactor that allows for processing semiconductor wafers in accordance with the methods of the present disclosure (e.g., facilitating deposition of epitaxial layers on surfaces of semiconductor wafers) can be used. In some examples, heating chamber 100 can be a Centura Epi reactor available from Applied Materials (Santa Clara, CA).

[0025] The chamber 100 includes a processing environment 102 in which a single semiconductor wafer 104 is processed. For example, the chamber 100 may be suitable for semiconductor wafer processing, such as chemical vapor deposition (CVD) growth (i.e., epitaxial growth) of a thin film on the wafer 104. Other suitable semiconductor wafer processing operations for the chamber 100 include, for example, heating the wafer 104, cleaning the wafer 104, and / or etching the wafer 104. The chamber 100 may also be suitable for processing multiple (i.e., two or more) semiconductor wafers 104 simultaneously.

[0026] Suitable semiconductor wafers 104 (which may also be referred to as "wafers" or "silicon wafers") include single crystal silicon wafers, such as those obtained, for example, by slicing a silicon wafer from an ingot formed by the Czochralski process or the floating zone melting process. Each semiconductor wafer 104 includes a front surface 142 and a back surface 144 that is generally parallel to the front surface 142. The front and back surfaces 142, 144 are typically perpendicular to the central axis of the wafer 104. A circumferential or peripheral edge 146 joins the front and back surfaces 142, 144. The semiconductor wafers 104 can have any suitable diameter, including, for example, a diameter of 150 millimeters (mm), 200 mm, 300 mm, or 450 mm.

[0027] The chamber 100 includes a first gas injection port 106a disposed at one end of the processing environment 102 and a gas exhaust port 108 disposed at the opposite end of the processing environment 102. The chamber 100 also includes a second gas injection port 106b (located between the first gas injection port 106a and the gas exhaust port 108). Figure 3 A gas manifold (not shown) disposed between the gas injection ports 106a and 106b and the processing environment 102 is used to guide the incoming gas 110 into the processing environment 102 enclosed by the upper window 112 and the lower window 114 through the first gas injection port 106a and the second gas injection port 106b.

[0028] In operation, an incoming process gas 110 flows through the gas manifold and into the processing environment 102 through the gas inlet 103 defined by each of the gas injection ports 106a and 106b. The gas 110 flows through the processing environment 102 and is exhausted through the gas exhaust port 108. The process gases 110 flowing through the inlet 103 defined by the gas injection ports 106a and 106b, respectively, can be the same or different.

[0029] The chamber 100 includes a carrier 120 within the processing environment 102 for supporting a semiconductor wafer 104. The carrier 120 is suitably configured to rotate the semiconductor wafer 104 during processing. Figure 3 As shown in FIG, the susceptor 120 is connected to a shaft 122, which is connected to a motor (not shown) of a rotation mechanism (not shown) for rotating the shaft 122, the susceptor 120, and the semiconductor wafer 104 about a vertical axis V of the chamber 100. The susceptor 120 can rotate the semiconductor wafer 104 at any suitable rotational speed. For example, the susceptor 120 and the semiconductor wafer 104 can rotate at a speed between 1 RPM and 100 RPM. Additionally and / or alternatively, the susceptor 120 can be attached to a pair of rotatable supports (not shown) for rotating the susceptor 120 during processing.

[0030] The chamber 100 may also include a preheat ring 126 surrounding the susceptor 120 within the processing environment 102. The preheat ring 126 allows the process gas to be brought up to temperature before contacting the semiconductor wafer 104. An outer edge 124 of the susceptor 120 and an inner edge of the preheat ring 126 are separated by an annular gap 125 to allow the susceptor 120 to rotate. The semiconductor wafer 104 is rotated to uniformly process the wafers in the chamber 100.

[0031] The incoming gas 110 may be heated before contacting the semiconductor wafer 104. Both the preheat ring 126 and the susceptor 120 are typically opaque to absorb the radiant heating light generated by high-intensity radiant heating lamps 128, which may be located above and below the processing environment 102. Equipment other than the high-intensity lamps 128 may be used to provide heat to the processing environment 102, such as, for example, resistive heaters and inductive heaters. Maintaining the preheat ring 126 and the susceptor 120 at a temperature above ambient temperature allows the preheat ring 126 and the susceptor 120 to transfer heat to the incoming gas 110 as the gas 110 passes through them. The diameter of the semiconductor wafer 104 is suitably smaller than the diameter of the susceptor 120 to allow the susceptor 120 to heat the incoming gas 110 before contacting the semiconductor wafer 104. The preheat ring 126 and the susceptor 120 may be constructed of, for example, silicon carbide or opaque graphite coated with silicon carbide.

[0032] An infrared temperature sensor such as a pyrometer (eg, sensor 188 ) may be mounted on reaction chamber 100 to monitor the temperature of susceptor 120 , preheat ring 126 , and / or semiconductor wafer 104 by receiving infrared radiation emitted by the susceptor, preheat ring, and / or wafer.

[0033] The upper and lower windows 112, 114 each have a generally annular body made of a transparent material such as quartz to allow radiant heating light to enter the processing environment 102 and onto the preheat ring 126, the susceptor 120 and the semiconductor wafer 104. The windows 112, 114 can be flat, or as Figure 1 , the windows 112, 114 can have a generally dome-shaped configuration. One or both of the windows 112, 114 can alternatively have an inwardly concave configuration. The upper and lower windows 112, 114 are coupled to upper and lower chamber walls 130, 132 of the chamber 100, respectively.

[0034] Upper and lower chamber walls 130 , 132 define the outer perimeter of the processing environment 102 and are adjacent to the gas injection ports 106 a , 106 b and the gas exhaust port 108 .

[0035] The chamber 100 may include upper and lower liners 134 and 136 disposed within the processing chamber to prevent reaction between the gas 110 and the chamber walls 130 and 132, which may be made of a metal material such as stainless steel. The liners 134 and 136 may be made of a suitable non-reactive material such as quartz. The outer periphery of the preheat ring 126 may be attached to the inner periphery of the lower liner 136. For example, the preheat ring 126 may be supported by an annular shelf-like protrusion 160 of the lower liner 136.

[0036] Figure 2 and 3 The semiconductor wafer 104 supported on the susceptor 120 in the heating chamber 100 is shown in greater detail. Figure 2 is the cross section of the heating chamber 100 and Figure 3 FIG is a top view of the heating chamber 100. The components of the chamber 100 are Figure 2 and 3 Omitted for ease of illustration and description.

[0037] refer to Figure 2 and 3 The carrier 120 is generally disc-shaped and includes a front surface 148 and a recess 150 formed in the front surface 148. The recess 150 is defined by sidewalls 152 that overhang the front surface 148. The recess 150 is sized and shaped to receive the semiconductor wafer 104 during processing. For example, Figure 3 , the recess 150 is generally circular and defined by a generally annular sidewall 152. The carrier 120 may have other overall dimensions without departing from the scope of the present disclosure. The carrier 120 may be sized and configured such that the recess 150 of the carrier 120 can accommodate semiconductor wafers 104 of any suitable diameter, including, for example, 150 mm, 200 mm, 300 mm, or 450 mm diameter wafers 104.

[0038] Semiconductor wafer 104 is positioned within recess 150 of carrier 120 and supported by shelf protrusions 154 extending between sidewalls 152 and recess floor 156. Wafer 104 is oriented within recess 150 such that shelf protrusions 154 support a portion of back surface 144 of wafer 104 proximate peripheral edge 146. Shelf protrusions 154 are angled downwardly toward recess floor 156 such that bottom surface 156 is spaced a distance from back surface 144 of wafer 104.

[0039] like Figure 2 and 3, when the semiconductor wafer 104 is positioned in the recess 150, the peripheral edge 146 of the wafer is spaced a distance from the sidewalls 152 of the carrier 120. The semiconductor wafer 104 can be positioned in the recess 150 manually or using an automated wafer transfer device, such as a robotic arm. The wafer 104 may not be perfectly centered within the recess 150, such that the distance between the peripheral edge 146 and the sidewalls 152 varies along the circumference of the wafer 104. The peripheral edge 146 of the wafer 104 is spaced a minimum distance D1 from the sidewalls 152 and a maximum distance D2 from the sidewalls 152. The difference between the minimum distance D1 and the maximum distance D2 is due to an off-center wafer positioned in the recess 150. The off-center wafer positioning can be due to, for example, wafer placement tolerances, movement of the wafer during placement, and / or thermal expansion.

[0040] Usually refer to Figures 1 to 3 In operation, the heating chamber 100 containing the susceptor 120 and the wafer 104 supported on the susceptor 120 can be used for the cleaning, etching and / or growth steps of an epitaxial deposition process. In an example epitaxial deposition process, an epitaxial silicon layer is grown on the front surface 142 of the semiconductor wafer 104. In this example, the silicon wafer 104 is introduced into the processing environment 102 at atmospheric pressure and placed on the susceptor 120. A cleaning gas (e.g., hydrogen, H2, or a mixture of H2 and an etchant gas (e.g., hydrogen chloride, HCl)) is introduced into the processing environment 102 as a process gas 110 through one or both of the first gas injection port 106a and the second gas injection port 106b to remove the native oxide layer on the front surface 142 and the back surface 144 of the semiconductor wafer 104.

[0041] After the native oxide layer has been removed from the front and back surfaces 142, 144 of the semiconductor wafer 104, the purge gas is terminated and the temperature in the heating chamber 100 is adjusted to a temperature suitable for the epitaxial deposition process (e.g., between about 600°C and about 1200°C). A deposition precursor gas is introduced as the process gas 110 through one or both of the first and second gas injection ports 106a, 106b. The deposition precursor gas may be a silicon-containing gas. Example silicon-containing gases include methylsilane, tetrahydrosilane (silane), trisilane, disilane, pentasilane, n-pentasilane, tetrasilane, dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), silicon tetrachloride (SiCl4), and the like. Depending on the target composition of the deposited epitaxial layer, the deposition precursor gas may include other materials, such as other semiconductor materials. The concentration of the gas may be determined based on the desired deposition effect (e.g., deposition rate). The deposition precursor gas flows over the front surface 142 of the semiconductor wafer 104 at a suitable flow rate (e.g., between about 1 liter / minute and about 100 liters / minute) and for a duration sufficient to grow an epitaxial layer (e.g., an epitaxial silicon layer) on the front surface 302 of the semiconductor wafer 104. The epitaxial layer may have a thickness between about 0.1 microns and about 200 microns. During deposition, the processing environment 102 may be at a suitable pressure (e.g., atmospheric pressure).

[0042] In addition to the deposition precursor gases, the process gas 110 introduced into the processing environment 102 during the deposition process may include a carrier gas, such as hydrogen, H2 (e.g., trichlorosilane in H2). The carrier gas may additionally and / or alternatively include argon, nitrogen, helium, or a combination thereof. The carrier gas may contact the back surface 144 of the semiconductor wafer 104 and carry outwardly diffused dopant atoms from the back surface 144 toward the gas exhaust port 108. The process gas 110 may also include an etchant gas, such as hydrogen chloride, HCl. The etchant gas may promote smoothing of the deposited epitaxial layer. Due to the reaction between the carrier gas and the deposition precursor gas, the etchant gas may also be generated in the processing environment. For example, in the case where the process gas 110 includes trichlorosilane in H2, HCl may be generated by the following equation:

[0043] SiHCl3(g)+H2(g)=Si(s)+3HCl(g).

[0044] The distance between the peripheral edge 146 of the wafer 104 and the sidewalls 152 can cause edge roll-off of the deposited epitaxial layer near the peripheral edge of the wafer 104, which affects the uniformity in thickness and flatness of the epitaxial layer deposited later on the wafer 104. For example, a smaller distance between the peripheral edge 146 and the sidewalls 152 can result in a smaller amount of deposited material accumulating near the peripheral edge 146 of the wafer 104 relative to the epitaxial layer deposited across the front surface 142. This creates a "dip" in the epitaxial layer deposited near the peripheral edge 146. Without being bound by a particular theory, the dip in the deposited epitaxial layer near the relatively small distance from the sidewalls 152 along the peripheral edge 146 can be attributed to reduced interaction between the process gas 110 and the peripheral edge 146 and / or to a relatively lower temperature at the peripheral edge 146 due to a relatively lower temperature of the carrier 120 at the sidewalls 152. A larger distance between the peripheral edge 146 and the sidewalls 152 can result in a larger amount of deposited material accumulating near the peripheral edge 146 of the wafer 104 relative to the epitaxial layer deposited across the front surface 142. This creates a "hike" in the deposited epitaxial layer near the peripheral edge 146. Without being bound by a particular theory, the hike in the deposited epitaxial layer in areas along the peripheral edge 146 that are near locations at a relatively large distance from the sidewalls 152 can be attributed to more interaction between the process gas 110 and the peripheral edge 146 because there is more space between the wafer 104 and the sidewalls 152 for the process gas to flow.

[0045] Due to different epitaxial deposition behaviors depending on the distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 of the carrier 120, the eccentric positioning of the wafer 104 within the groove 150 can affect the uniformity in thickness and flatness of the wafer 104 after epitaxy. In other words, due to the eccentric positioning within the groove 150, the edge roll-off of the deposited epitaxial layer can vary along the circumferential extent of the wafer 104. For example, the region on the front surface 142 of the wafer 104 near the peripheral edge 146 where the wafer 104 is spaced a maximum distance D2 from the sidewall 152 (e.g., typically at Figure 3 The region on the front surface 142 of the wafer 104 near the peripheral edge 146 where the wafer 104 is spaced a minimum distance D1 from the sidewall 152 (e.g., typically at Figure 3 The region indicated at 192 in FIG. 1 may accumulate a relatively small amount of deposited epitaxial material. As a result, the deposited epitaxial layer may have rises and falls along the circumferential extent of the wafer 104 near the peripheral edge 146, resulting in a non-uniform thickness and poor flatness of the wafer 104 after epitaxy.

[0046] Still refer to Figures 1 to 3, the heating chamber 100 includes an optical sensor 158 for measuring the distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 of the carrier 120. The optical sensor 158 may be, for example, a camera. Suitably, the optical sensor 158 is located outside the processing environment 102 and above the upper window 112. The optical sensor 158 may suitably measure the distance between the peripheral edge 146 and the sidewall 152 over the entire or substantially entire circumference of the wafer 104. For example, the optical sensor 158 may measure at a single location between the peripheral edge 146 of the wafer 104 and the sidewall 152 and continue to collect measurements while the wafer 104 is placed in and rotated by the carrier 120. Although one optical sensor 158 is shown in this example, more than one (i.e., two or more) optical sensors 158 may be included. Each optical sensor 158 may collect measurements at a different location between the peripheral edge 146 and the sidewall 152.

[0047] The optical sensor 158 can collect measurements of the distance between the peripheral edge 146 and the sidewall 152 in any suitable manner. For example, the optical sensor 158 can be connected to the controller 140, which can determine the distance between the peripheral edge 146 and the sidewall 152 based on the measurements collected by the optical sensor 158. Additionally or alternatively, the optical sensor 158 can be connected to a user interface that displays the collected measurements to an operator. The measurements collected by the optical sensor 158 can be in units of length (e.g., metric units such as mm), or can be in relative units. For example, the optical sensor 158 can collect measurements in arbitrary units relative to a reference distance. Thus, references to "measuring a distance," "determining a distance," "collecting measurements of a distance," and the like, when referring to the distance between the peripheral edge 146 and the sidewall 152, are not limited to a particular measurement technique. The measurements collected by the optical sensor 158 can determine areas along the circumference of the wafer 104 where edge roll may occur. For example, measurements collected by optical sensor 158 may determine a region of the wafer near peripheral edge 146 where wafer 104 is spaced a minimum distance D1 from sidewall 152 (eg, Figure 3 ), and the wafer region near the peripheral edge 146 where the wafer 104 is spaced a maximum distance D2 from the sidewall 152 (e.g., Figure 3 area 194 in the image).

[0048] In an example method, processing conditions within the heating chamber 100 are controlled and / or adjusted (collectively referred to as "modulated") (e.g., using the controller 140) based on a determined distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 of the carrier 120. The processing conditions may include, for example, the flow rate of the process gas 110 introduced into the processing environment 102 and / or the heat supplied to the processing environment 102. Based on the determined distance between the peripheral edge 146 of the wafer 104 and the sidewall 152, the processing conditions are modulated to control the deposition rate of the process gas 110 near the peripheral edge 146 of the wafer 104. As a result, greater uniformity in the thickness and flatness of the wafer 104 after epitaxy can be achieved. For example, the processing conditions may be modulated to increase the amount of deposited material on an area of ​​the wafer 104 where the wafer 104 is located near the peripheral edge 146 at a minimum distance D1 from the sidewall 152. Processing conditions may additionally or alternatively be modulated to reduce the amount of deposited material on a region of wafer 104 where wafer 104 is located near peripheral edge 146 at a maximum distance D2 from sidewall 152 .

[0049] like Figure 1 , the heating chamber 100 also includes a controller 140. The controller 140 is configured to control the operation of the heating chamber 100 (e.g., by modulating one or more processing conditions of the heating chamber). The controller 140 can be configured to control the operation of the heating chamber 100 based on a determined distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 of the susceptor 120 to thereby control the deposition rate of the process gas 110 near the peripheral edge 146 of the wafer 104. For example, the controller 140 can modulate the flow rate of the process gas 110 introduced into the processing environment 102 and / or the heat supplied to the processing environment 102 based on the determined distance between the peripheral edge 146 of the wafer 104 and the sidewall 152.

[0050] The controller 140 may include any suitable computer and / or other processing unit, including any suitable combination of computers, processing units, and / or the like that are communicatively connected to one another and can operate independently or within a connection (e.g., the controller 140 may form all or part of a controller network). The controller 140 may include one or more modules or devices, one or more of which may be enclosed within a single housing or remote from one another. The controller 140 may include one or more processors and associated memory devices configured to perform various computer-implemented functions (e.g., the functions disclosed herein). As used herein, the term "processor" refers not only to integrated circuits, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits. Additionally, the memory device of the controller 140 may be or include a memory element, including, but not limited to, computer-readable media (e.g., random access memory (RAM)), computer-readable non-volatile media (e.g., flash memory), a floppy disk, a compact disk read-only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disk (DVD), and / or other suitable memory elements. Such memory devices may be configured to store suitable computer-readable instructions that, when implemented by a processor, configure or cause the controller 140 to perform the various functions described herein, including, but not limited to, controlling the operation of the heating chamber 100 .

[0051] The controller 140 can communicate with one or more components of the heating chamber 100 (e.g., the optical sensor 158, the one or more spot heating modules 170, the one or more gas injection ports 106a, 106b, the gas manifold, the one or more temperature sensors 188, the rotation mechanism of the carrier 120, and / or other components) via a communication interface communicatively coupled to one or more of these components. The communication interface may include, but is not limited to, a wired network adapter, a wireless network adapter, a mobile telecommunications adapter, a serial communication adapter, or a parallel communication adapter. The communication interface can receive data signals from or transmit data signals to one or more components of the heating chamber 100 (e.g., the optical sensor 158, the one or more spot heating modules 170, the one or more gas injection ports 106a, 106b, the gas manifold, the one or more temperature sensors 188, the rotation mechanism of the carrier 120, and / or other components). The controller 140 may also include a presentation interface coupled to one or more of the processors. The presentation interface can present information to an operator of the heating chamber 100, such as a user interface. In one embodiment, the presentation interface includes a display adapter (not shown) coupled to a display device (not shown), such as a cathode ray tube (CRT), a liquid crystal display (LCD), an organic LED (OLED) display, or an "electronic ink" display. In some embodiments, the presentation interface includes one or more display devices. Additionally, or alternatively, the presentation interface includes an audio output device (not shown), such as, but not limited to, an audio adapter, a speaker, or a printer (not shown). The controller 140 may also include a user input interface coupled to one or more of the processors and operable to receive input from an operator. The user input interface may include, for example, but not limited to, a keyboard, a pointing device, a mouse, a stylus, one or more input buttons, a touch-sensitive panel (such as, but not limited to, a touchpad or a touch screen), and / or an audio input interface (such as, but not limited to, a microphone). A single component (such as a touch screen) may simultaneously serve as a display device for both the presentation interface and the user input interface.

[0052] Still refer to Figures 1 to 3The heating chamber 100 can be configured to modulate localized heating within the processing environment 102 to control the deposition rate of the process gas 110 near a target region of the wafer 104 based on a determined distance between the peripheral edge 146 and the sidewalls 152 of the wafer 104. Localized heating can be controlled by independently controlling (e.g., using a controller 140) high-intensity radiant heating lamps 128, which can be located above and below the processing environment 102. Additionally or alternatively, localized heating can be controlled by selectively controlling (e.g., using a controller 140) selected groups (or "radial zones") of the heating lamps 128 to control the temperature of various regions of the semiconductor wafer 104 during processing. Independently controlling the heating lamps 128, or controlling independent radial zones of the heating lamps 128, enables control of deposition thickness uniformity by adjusting the localized temperature of the reaction site to compensate for edge roll-off effects, for example, induced by the distance between the peripheral edge 146 and the sidewalls 152. The heating lamps 128, or zones thereof, can be powered individually using separate power supplies or through power distribution control between the zones.

[0053] The heating chamber 100 may also include a spot heating module 170. The spot heating module 170 includes one or more spot heaters 172. Each spot heater 172 supplies localized heat within the processing chamber 102. The spot heaters 172 are used to appropriately supply localized heat near one or more target areas on the semiconductor wafer 104 during processing. The target area of ​​the wafer 104 for localized heating may be an area where the peripheral edge 146 is spaced a certain distance from the sidewall 152 so that edge roll-off is expected to occur. For example, the spot heaters 172 may be used to supply localized heat to a target area of ​​the wafer 104 near the peripheral edge 146 within the processing chamber 102 (e.g., typically at Figure 3 192 in the figure), where the wafer 104 is located at a minimum distance D1 from the sidewall 152. Thus, the spot heating module 170 can promote more uniform epitaxial layer thickness and wafer flatness by facilitating the reduction or elimination of edge roll-off. Localized heating using the spot heater 172 can be controlled via the controller 140.

[0054] For example, each spot heater 172 is connected to an electromagnetic radiation source 174 or multiple electromagnetic radiation sources 174 via a corresponding optical fiber 176. The electromagnetic radiation source 174 can be directly disposed on the spot heater 172 rather than being connected to the spot heater 172 by an optical fiber. For example, the electromagnetic radiation source 174 can be a pulsed electromagnetic radiation source or a continuous wave (CW) electromagnetic radiation source. Additionally or alternatively, the electromagnetic radiation source 174 can be a high-energy radiation source, such as a laser source including, for example, crystal lasers, laser diodes and arrays, and vertical cavity surface emitting lasers (VCSELs). High-intensity LED light sources can also be used as electromagnetic radiation sources, and collimators can be used to collimate the light emitted from the LED light source to form a beam. The wavelength of the emitted radiation can typically be in the ultraviolet, visible, and / or infrared spectrum, from about 200 nm to about 900 nm (e.g., 810 nm), and the emitted radiation can be monochromatic, narrowband, broadband, or ultra-broadband, such as white laser light.

[0055] Electromagnetic radiation source 174 emits high-intensity electromagnetic radiation, which is routed to spot heater 172 via optical fiber 176. Spot heater 172 directs the exit end of optical fiber 176 toward a target location in processing environment 102, such as a target area of ​​wafer 104 located on carrier 120. Optical fiber 176 generates a radiation beam from the radiation emitted by electromagnetic radiation source 174 toward the target location. The end of optical fiber 176 may have one or more optical features (including lenses, faceted surfaces, diffuser surfaces, filters, and other coatings) to direct or condition the electromagnetic radiation exiting the optical fiber. Alternatively, one or more optical elements may be coupled to the end of optical fiber 176 in spot heater 172. Thus, spot heater 172 is configurable and interchangeable. The radiation beams from electromagnetic radiation source 174 may have the same wavelength or different wavelengths. In one embodiment, the radiation beams have different wavelengths for heating areas of wafer 104 and / or different materials formed on wafer 104.

[0056] like Figure 2 As shown in FIG, the spot heater 172 includes a collimator 178 held by a holder 180. The collimator 178 is an optical element that collimates radiation from one of the electromagnetic radiation sources 174 (e.g., by using a suitably designed lens). The collimator 178 has a first end into which radiation from the electromagnetic radiation source 174 is input (e.g., by directing the output of a laser source into an opening in the first end). The collimator 178 has a second end with an opening in which a collimating optical assembly is housed. A laser or laser source can be mounted directly to the collimator 178 by inserting the laser's beam exit portion into the first end of the collimator 178, such that radiation emitted by the laser passes through the collimator 178 and through the second end having the collimating optical assembly (which may be a lens or a collection of lenses). Alternatively, the collimator 178 can be replaced with an optical fiber 176 or electromagnetic radiation source 174, and then the holder 180 directly holds the optical fiber 176 or electromagnetic radiation source 174.

[0057] Holder 180 is mounted on a stage 182. Stage 182 includes a wedge 184 and a slide 186. Stage 182 is secured to heating chamber 100, for example, to a base or support thereof. For example, stage 182 may be secured to a roof of heating chamber 100 that encloses processing equipment, such as heat lamps 128. Additionally and / or alternatively, stage 182 may be secured to a reflector mounted on processing equipment (e.g., heat lamps 128) within heating chamber 100. Slide 186 allows for linear movement of stage 182 relative to heating chamber 100 during processing. For example, slide 186 may be linearly moved using a set screw or an actuator.

[0058] Wedge 184 includes a surface that contacts holder 180. The surface of wedge 184 forms an angle relative to a plane generally parallel to front surface 148 of carrier 120. The angle formed by the surface of wedge 184 can be adjusted, for example, by a detent located in wedge 184. Adjusting this angle enables targeted localized heating by spot heater 172. Aiming of spot heater 172 is also accomplished by adjusting the position of stage 182 via slide 186. Because the angle formed by the surface of wedge 184 and the position of slide 186 can be adjusted by the actuator, the position of the beam spot emitted by spot heater 172 is also adjusted. Wedge 184, slide 186, and the support of heating chamber 100 to which stage 182 is secured can be made of a material (e.g., quartz) that is transparent to the radiant energy emitted from electromagnetic load source 174 (transmitting at least 95% of the radiant energy). Additionally or alternatively, an opening can be formed through the wedge 184, slide 186, and supports of the heating chamber 100 to allow the beam (e.g., laser beam) from the collimator 178 to pass through a target area on the semiconductor wafer 104. The opening is suitably large enough to accommodate movement of the wedge 184 and / or slide 186.

[0059] The spot heater 172 can be aimed by performing a manual calibration process. During the alignment process, the spot heater 172 is energized to generate a guide beam. The operator can see a spot from the guide beam falling on the carrier 120. The carrier 120 can be rotated to align the area to be heated by the spot heater 172 with the guide beam. Then, the positioning device of the spot heater 172 (such as the slide 186 and the wedge 184) can be operated to align the spot heater 172 with the target area to be heated. For example, the target area to be heated can be an area of ​​the wafer 104 where the wafer 104 is located near the peripheral edge 146 of the sidewall 152 at a minimum distance D1 (typically at Figure 3 192 instructions in the ).

[0060] The collimator 178 may be connected to a movement device (not shown) that facilitates movement of the collimator 178 within the holder 180. The movement device may be disposed between the holder 180 and the collimator 178. The movement device may be, for example, a device that rotates the collimator 178 about its longitudinal axis. During processing, the collimator 178 may be in a first position during a first processing step, and the collimator 178 may be rotated to a second position before or during a second processing step. For example, the rotation of the collimator 178 may change the shape and / or size of the beam spot of the radiation beam emitted from the collimator 178 onto the carrier 120 and / or the wafer 104. During processing, the movement device may continuously rotate the collimator 178 about its longitudinal axis (e.g., in a clockwise or counterclockwise rotational direction) to dynamically change the shape of the beam spot. As discussed above, the carrier 120 and wafer 104 may also be rotated during processing. The rotation of the collimator 178 can be synchronized with the rotation of the wafer 104 to provide precise heating to one or more target areas on the wafer 104. Additionally and / or alternatively, the motion device can cause the collimator 178 to rotate and oscillate within a predetermined angular range (e.g., between negative 60 degrees and 60 degrees). The oscillation of the collimator 178 can be synchronized with the rotation of the wafer 104. In examples where the collimator 178 is replaced with an optical fiber 176 or an electromagnetic radiation source 174, the motion device can also be coupled to the optical fiber 176 or the electromagnetic radiation source 174. The motion device can rotate the optical fiber 176 or the electromagnetic radiation source 174 as described above for the collimator 178.

[0061] The movement device of the collimator 178 can be a controlled motion device that produces periodic motion (e.g., vibration, circular motion, or linear motion). The motion produced by the motion device is transferred to the collimator 178, or alternatively, to the optical fiber 176 or the electromagnetic radiation source 174. The collimator 178 can move the beam spot as the movement device moves the collimator 178. The movement of the beam spot suitably illuminates an exposure area on the wafer 104 that is larger than the area of ​​the beam spot. Additionally and / or alternatively, the collimator 178 can illuminate overlapping areas on the wafer 104, approximately illuminated by a large beam spot that is larger than the beam spot produced by the electromagnetic radiation source 174. As the collimator 178 moves, the electromagnetic radiation source 174 produces a continuous electromagnetic radiation beam that illuminates an exposure area on the wafer 104 that is larger than the area of ​​the beam spot as the electromagnetic radiation beam passes through the moving collimator 178. During processing, as the wafer 104 rotates, the large beam spot defines an annular heating zone.

[0062] As the electromagnetic radiation beam passes through the mobile collimator 178, the electromagnetic radiation source 174 can be pulsed by the mobile collimator 178 to form a large beam spot on the wafer 104. During processing, as the wafer 104 rotates, the large beam spot heats discrete areas on the wafer 104. The pulsing of the electromagnetic radiation beam can be synchronized with the rotation of the wafer 104 and / or with the movement of the beam spot. For example, the beam can be pulsed at a frequency related to the vibration frequency of the collimator 178. The related frequencies can deliver radiation pulses to overlapping areas of the wafer 104, such that an exposure area of ​​the wafer 104 (larger than the area of ​​any of the pulses) is exposed to the pulsed radiation. The duration of the pulsing by the mobile collimator 178 determines the angular sweep of the illumination along the annular or partially annular heating zone.

[0063] The collimator 178 can be moved continuously or periodically, for example, as pulses of the electromagnetic radiation beam pass through the collimator 178. In one example, the beam can be pulsed for a first duration when the collimator 178 is moved, and for a second duration when the collimator 178 is not moved. In this example, a first exposure area of ​​the wafer 104 corresponding to the first duration is larger than an area of ​​the beam, while a second exposure area corresponding to the second duration has substantially the same size as the beam.

[0064] Example methods described herein can include modulating localized heating of the wafer 104 by adjusting the shape and / or size of a beam spot emitted by a spot heater 172 for heating radiation. The spot heater 172 is configured to dynamically control the shape and / or size of the beam spot without modifying the optics of the system.

[0065] The beam spot can also be formed by multiple (e.g., two) spot heaters 172 positioned and oriented so that the beam spots generated by each spot heater 172 overlap. The cooperating spot heaters 172 can include electromagnetic radiation sources 174 that generate radiation beams of the same or different wavelengths. For example, two cooperating spot heaters 172 can include a blue laser and a green laser, respectively, and the beam spot generated by the overlapping beam spots includes a blue portion and a green portion.

[0066] The beam spot can also be formed by moving the collimator 178 and / or by actuation (e.g., vibrating the slider 186). The beam spot can also be formed by actuation (e.g., moving the angle formed by the surface of the wedge 184 and a plane generally parallel to the front surface 148 of the carrier 120). Movement of the collimator 178, the slider 186, and / or the angle of the wedge 184 surface can suitably form a racetrack-shaped beam spot. The pair of wedges 184 of the cooperating spot heater 172 can be precisely machined using an offset angle to achieve the desired beam spot shape.

[0067] The beam spot generated by the one or more spot heaters 172 can have different orientations relative to the movement of the wafer 104 during processing. For example, the beam spot can have an elliptical shape, and the major axis of the elliptical beam spot can be oriented substantially perpendicular to the direction of movement (e.g., the rotational direction) of the wafer 104. When the major axis of the beam spot is substantially perpendicular to the direction of movement of the wafer 104, the width of the beam spot (i.e., the effective length of the major axis of the beam spot) can be adjusted without changing the optics of the spot heaters 172. For example, the width of the beam spot can be changed by rotating the collimator 178. Rotating the collimator 178 can cause the beam spot orientation to rotate so that the major axis of the elliptical beam spot is no longer substantially perpendicular to the direction of movement of the wafer 104, resulting in a narrower width of the beam spot. This technique is also applicable to linear beam spots.

[0068] The heating chamber 100 may also include one or more sensors 188 (e.g., pyrometers) disposed on a support member of the chamber 100 (e.g., a top cover or reflector) to which the one or more spot heaters 172 are secured. Each spot heater 172 may also include a sensor 188. The collimator 178 and the sensors 188 may both be disposed on a single stage 182. The one or more sensors 188 may be used (e.g., by the controller 140) to modulate the power to the spot heaters 172. For example, the controller 140 may receive temperature data from the sensors 188 and may increase or decrease the power to the spot heaters 172 based on the temperature data. In this system, the combination of the sensors 188 and the spot heaters 172 may be used for closed-loop or open-loop control to adjust the spot heaters 172 based on the readings from the sensors 188.

[0069] In an example method, localized heating within the processing environment 102 can be modulated (e.g., using the controller 140) based on a determined distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 of the carrier 120 to control the deposition rate of different regions of the wafer 104 near the peripheral edge 146. Thus, greater uniformity in the thickness and flatness of the wafer 104 after epitaxy can be achieved. For example, the controller 140 can modulate the localized heating to increase the deposition rate of regions of the wafer 104 near the peripheral edge 146 (e.g., Figure 3 152) where the wafer 104 is at a minimum distance D1 from the sidewall 152. This can be accomplished by controlling the one or more high-intensity radiant heating lamps 128 and / or the one or more spot heaters 172 of the spot heating module 170 to selectively increase localized heating within the processing environment 102 near the peripheral region of the wafer 104 that is at the minimum distance D1 from the sidewall 152. Additionally or alternatively, the controller 140 can modulate the localized heating to reduce the amount of deposited material in the region near the peripheral edge 146 (e.g., Figure 3194) where the wafer 104 is located at a maximum distance D2 from the sidewall 152. This can be achieved by controlling the one or more high-intensity radiant heating lamps 128 and / or the one or more spot heaters 172 of the spot heating module 170 to selectively reduce localized heating within the processing environment 102 near the peripheral edge region of the wafer 104 located at the maximum distance D2 from the sidewall 152. As described above, the sensor 120 and the wafer 104 can be rotated within the processing environment 102. The controller 140 can control the modulation of the localized heating to be synchronized with the rotation of the sensor 120 and the wafer 104.

[0070] refer to Figure 3 The heating chamber 100 can also be configured to control the flow rates of the process gases 110 flowing within the processing environment 102 and the flow interactions between the process gases 110 (e.g., via the controller 140) to control the deposition rate of the process gases 110 near a target area of ​​the wafer 104 based on a distance determined between the peripheral edge 146 of the wafer 104 and the sidewall 152. The flow interactions between the process gases 110 are facilitated by the first gas injection port 106a and the second gas injection port 106b. The injection ports 106a and 106b may also be referred to as gas inlets 106a and 106b. The first injection port 106a supplies the first process gas 110a to the processing environment 102 in a first gas direction, and the second gas injection port 106b supplies the second process gas 110b to the processing environment 102 in a second gas direction that intersects the first gas direction. The intersection between the first and second process gases 110a and 110b creates a cross-flow interaction of the process gases within the processing environment 102, suitably above the front surface 142 of the wafer 104. Controlled flow interaction between the process gases within the processing environment 102 may provide advantages, such as controlling the thickness and / or composition uniformity of deposited epitaxial layers.

[0071] like Figure 3 As shown in FIG, the susceptor 120 defines an X-axis and a Y-axis. The X-axis and the Y-axis are generally perpendicular to each other and intersect at the center C of the susceptor 120. Each of the X-axis and the Y-axis extends across the front surface 148 and the recess 150 of the susceptor 120. The first gas inlet 106a and the gas exhaust 108 are disposed on opposite sides of the susceptor 120 and are generally aligned along the X-axis. The second gas inlet 106b is disposed between the first gas inlet 106a and the gas exhaust 108 to supply a second process gas 110b at an angle to the first process gas 110a supplied by the first gas inlet 106a. The second gas inlet 106b is separated from the first gas inlet 106a by an azimuth angle 190. The azimuth angle 190 can be any angle to facilitate functioning of the heating chamber 100 as described herein. For example, the azimuth angle 190 can be between 0 and 145 degrees, measured on either side of the susceptor 120. exist Figure 3 In the example shown in , the azimuth angle 190 is approximately 90 degrees. Figure 3 The positioning of the second gas inlet 106b in FIG. 1 is an example and the second gas inlet 106b may include other positions relative to the first gas inlet 106a.

[0072] The first gas inlet 106a supplies a first process gas 110a in a first direction (generally indicated by arrow 110a) onto the front surface 142 of the wafer 104. The term "process gas" refers to both a single gas and a mixture of multiple gases. For example, the process gas 110a may include a combination of a deposition precursor gas (e.g., trichlorosilane, TCS) and a carrier gas (e.g., H2) and / or an etchant gas (e.g., HCl). The term "direction" refers to the direction in which the process gas exits the inlet. After exiting the respective inlet, at least a portion of the process gas may be deflected from the exit direction within the processing environment 102 to cover the front surface 142 of the wafer 104. In the example chamber 100, the first direction of the first process gas 110a is generally parallel to the front surface 142 of the wafer 104 and is generally directed toward the opposite gas exhaust port 108.

[0073] The first gas inlet 106a may comprise a single port defining a gas inlet 103, wherein the first process gas is provided through the port, such as Figure 3 Schematically shown in FIG, 1 , or may include multiple secondary inlets (not shown) that collectively define a gas inlet 103. For example, the first gas inlet 106a may include up to five inlets, although more or fewer secondary inlets (e.g., one or more) may be provided. Each secondary inlet may provide a first process gas 110a, which may be, for example, a mixture of several process gases. Additionally and / or alternatively, one or more secondary inlets may provide one or more process gases 110a that are different from at least one other secondary inlet. The process gases supplied by the first gas inlet 106a may be substantially uniformly mixed after exiting the first gas inlet 106a to form the first process gas 110a. For example, the process gases may generally not mix together after exiting the first gas inlet 106a, such that the first process gas 110a has a purposeful, non-uniform composition. The flow rate, process gas composition, and the like at the first gas inlet 106a or each of its secondary inlets may be independently controlled. In some embodiments, during processing, some of the secondary inlets may be idle or pulsed to, for example, achieve a desired flow interaction with the second process gas 110b provided by the second gas inlet 106b. Furthermore, in embodiments where the first gas inlet 106a includes a single port, the single port may be modulated (e.g., by pulsing or by restricting flow) to achieve a desired flow interaction with the second process gas 110b.

[0074] The second gas inlet 106b may be identical or substantially similar in design to the first gas inlet 106a. As described above for the first gas inlet 106a, the second gas inlet 106b may include a single port, such as Figure 3 Schematically shown in . Additionally and / or alternatively, the second gas inlet 106b may include multiple secondary inlets, as described above for the first gas inlet 106a. Each secondary inlet may provide a second process gas 110b, or one or more process gases different from at least one other secondary inlet. The process gases may be substantially uniformly mixed after exiting the second gas inlet 106b to form the second process gas 110b. The process gases may generally not be mixed together after exiting the second gas inlet 106b such that the second process gas 110b has a purposeful, non-uniform composition. The flow rate, process gas components, and the like at the second gas inlet 106b or each of its secondary inlets may be independently controlled. For example, during processing, the second gas inlet 106b or some or all of its secondary inlets may be idle or pulsed to achieve a desired flow interaction with the first process gas 100a provided by the first gas inlet 106a.

[0075] The second gas inlet 106b supplies the second process gas 110b in a second direction that intersects the first direction. Suitably, the second direction intersects the first direction such that cross-flow interaction between the first process gas 110a and the second process gas 110b occurs at the front surface 142 of the wafer 104. The relationship between the first direction of the first process gas 110a and the second direction of the second process gas 110b can be defined, at least in part, by an azimuth angle 190. The azimuth angle 190 is measured about the central axis of the susceptor 120 (i.e., the axes extending generally perpendicular to the X and Y axes and intersecting at the center C) between the outlets of the first gas inlet 106a and the second gas inlet 106b. The azimuth angle 190 can be up to approximately 145 degrees, or between approximately 0 and approximately 145 degrees. For example, the azimuth angle 190 can be less than 90 degrees to position the second gas inlet 106b closer to the first gas inlet 106a than to the gas exhaust port 108. In another example, the azimuth angle 190 may be greater than 90 degrees to cause the second gas inlet 106b to be positioned closer to the gas exhaust 108 than the first gas inlet 106a. Figure 3 , the azimuth angle 190 is approximately 90 degrees. The azimuth angle 190 may be selected to provide a desired amount of cross-flow interaction between the first process gas 110a and the second process gas 110b.

[0076] Either or both of the first and second directions of the first and second process gases 110a, 110b may be substantially parallel to the front surface 142 of the wafer 104, or angled relative to the front surface 142 of the wafer 104 (i.e., angled relative to an XY plane defined by the X and Y axes). For example, the first gas inlet 106a may have one or more secondary inlets oriented such that the first direction is angled relative to the XY plane, and / or the second gas inlet 106b may have a similar configuration with one or more of the secondary inlets oriented such that the second direction is angled relative to the XY plane.

[0077] In one example, the azimuth angle 190 is zero degrees. In such an example, the first gas inlet 106a and the second gas inlet 106b can be arranged in vertical alignment, for example, stacked on top of each other or integrated into a single unit. In such an embodiment, due to the angular orientation of the second direction and the parallel orientation of the first direction relative to the XY plane, and / or due to the angular orientation of the first direction and the parallel orientation of the second direction relative to the XY plane, the first and second directions are different (even though the azimuth angle 190 between them is zero degrees). Therefore, flow interaction between the first process gas 110a and the second process gas 110b can occur even when the azimuth angle 190 is zero degrees.

[0078] The azimuth angle 190 can define the difference between the first and second directions of the first process gas 110a and the second process gas 110b. For example, where the first and second directions are both parallel to the XY plane and the first and second gas inlets 106a and 106b are oriented such that the first and second directions are each aligned across a diameter of the susceptor 120 (and / or wafer 104), the azimuth angle 190 generally defines a flow interaction angle. In these examples, the azimuth angle 190 is suitably non-zero such that the first and second directions differ, and thus flow interaction can be achieved.

[0079] The first gas inlet 106a and the second gas inlet 106b can be positioned at different heights to further facilitate flow interaction between the first process gas 110a and the second process gas 110b. For example, the first gas inlet 106a can be positioned at a first height and the second gas inlet 106b can be positioned at a second height above the front surface 142 of the wafer 104. The first and second heights can be adjustable. For example, each height can be set before the wafer 104 is processed in the chamber 100, or each inlet 106a and 106b can be mounted on a movable platform (not shown), or the susceptor 120 can be moved along its central axis to adjust the first and second heights (e.g., where the susceptor 120 can be moved vertically to place the wafer 104 in different processing planes). The second height of the second gas inlet 106a can be greater than, less than, or equal to the first height of the first gas inlet 106a. In such embodiments, the second direction of the second process gas 110b can be parallel to the XY plane or angled relative to the XY plane.

[0080] exist Figure 3 In the example shown in FIG, the first gas inlet 106a is oriented such that a first direction of the first process gas 110a is generally aligned with a diameter of the susceptor 120 and / or the wafer 104. For example, the first direction is generally aligned with the X-axis. The second gas inlet 106b is angled relative to the central axis of the susceptor 120 (i.e., the axes extend generally perpendicular to the X-axis and the Y-axis and each intersects at the center C). Thus, the second direction is not aligned with the diameter of the susceptor 120 and / or the wafer 104. In other examples, the second gas inlet 106b may be oriented such that the second direction is aligned with a diameter of the susceptor 120 and / or the wafer 104 (e.g., the second direction may be generally aligned with the Y-axis). In these examples, the first gas inlet 106a may be oriented as described above or the first gas inlet 106a may be angled relative to the central axis of the susceptor 120.

[0081] The second gas inlet 106b may be angled relative to the central axis such that the second direction is directed toward a region of the wafer 104 near the peripheral edge 146 where the wafer 104 is a minimum distance D1 from the sidewall 152, typically at Figure 3192 in FIG. Region 192 may also be referred to herein as a first peripheral edge region 192. The orientation of the first and second gas inlets 106a, 106b may increase cross-flow interaction between the first and second process gases 110a, 110b near the first peripheral edge region 192 of the wafer 104, where a smaller amount of epitaxial material may otherwise be deposited due to the minimum distance D1 between the peripheral edge 146 and the sidewall 152. Increasing the cross-flow interaction between the first and second process gases 110a, 110b at the first peripheral edge region 192 may be desirable where both process gases 110a and 110b include a deposition precursor gas (e.g., trichlorosilane (TCS)) such that the deposition rates of the first and second process gases 110a, 110b near the first peripheral edge region 192 of the wafer 104 may be increased. Additionally or alternatively, cross-flow interaction between the first process gas 110a and the second process gas 110b, both comprising deposition precursor gases, may be reduced near a region of the wafer 104 near the peripheral edge 146 where the wafer 104 is a maximum distance D2 from the sidewall 152, typically at Figure 3 194 in FIG. Region 194 may also be referred to herein as a second peripheral edge region 194. Because the second direction of the second process gas 110b is not directed toward the second peripheral edge region 194, cross-flow interactions may be reduced at the second peripheral edge region 194. Consequently, the deposition rates of the first process gas 110a and the second process gas 110b near the second peripheral edge region 194 may be reduced. This may be advantageous because the second peripheral edge region 194, which defines the maximum distance D2, may otherwise be susceptible to a relatively large amount of epitaxial material.

[0082] In other examples, the first and second gas inlets 106a, 106b can be oriented to increase cross-flow interaction between the first and second process gases 110a, 110b near the second peripheral edge region 194 of the wafer 104, where a greater amount of epitaxial material can otherwise be deposited due to the maximum distance D2 between the peripheral edge 146 and the sidewall 152. Increasing cross-flow interaction between the first and second process gases 110a, 110b at the second peripheral edge region 194 can be desirable where at least one of the process gases 110a and 110b includes an etchant gas (e.g., hydrogen chloride, HCl) such that deposition rates of the first and second process gases 110a, 110b near the second peripheral edge region 194 of the wafer 104 can be reduced.

[0083] The angle at which the second gas inlet 106b directs the second direction of the second process gas 110b can depend on the azimuth angle 190. For example, the second gas inlet 106b can be positioned such that the azimuth angle 190 is approximately 90 degrees, and in such an example, the second gas inlet 106b can be angled relative to the central axis of the susceptor 120 such that the second direction forms an angle between 15 and 45 degrees (e.g., between 20 and 40 degrees, or between 25 and 35 degrees (e.g., 30 degrees)) with the central axis of the susceptor 120. In other embodiments where the azimuth angle 190 is greater than or less than 90 degrees, other angles of the second gas inlet 106b can be used to target the same peripheral edge region of the wafer 104. Furthermore, in some embodiments, the second gas inlet 106b can be substantially aligned with the diameter of the susceptor 120 and / or the wafer 104, and / or the first gas inlet 106a can be angled relative to the central axis of the susceptor 120 as described above.

[0084] As described above, the wafer 104 is suitably rotated during processing. Therefore, the orientation of the first and second gas inlets 106a, 106b for controlling the flow interaction of the first and second process gases 110a, 110b near target regions of the wafer 104 (e.g., increasing the flow interaction near the first peripheral edge region 192 and / or reducing the flow interaction near the second peripheral edge region 194) may be sufficient only during a portion of processing. As the wafer rotates, the second peripheral edge region 194 approaches a region where flow interaction is intentionally increased, while the first peripheral edge region 192 approaches a region where flow interaction is intentionally reduced. Generally, it is difficult to alter the angle and / or orientation of the first and second gas inlets 106a, 106b during processing. Therefore, to compensate for the rotation of the wafer 104 during processing, the flow rates of the process gases 110a and 110b may be modulated (e.g., via the controller 140).

[0085] The flow rates of the process gases 110a and 110b are suitably modulated such that the deposition rates of the first process gas 110a and the second process gas 110b increase near a first peripheral edge region 192 of the wafer 104 and the deposition rates of the first process gas 110a and the second process gas 110b decrease near a second peripheral edge region 194. Furthermore, the modulation of the flow rates of the process gases 110a and 110b is suitably synchronized with the rotation of the wafer 104. For example, as the wafer rotates, the flow rates of the process gases 110a and 110b may increase as the first peripheral edge region 192 approaches the region targeted by the angles and orientations of the first and second gas inlets 106a and 106b, and the flow rates of the process gases 110a and 110b may decrease as the second peripheral edge region 194 approaches the region targeted by the angles and orientations of the first and second gas inlets 106a and 106b. Modulating the flow rates of the process gases 110a and 110b may additionally and / or alternatively include modulating the flow rates of specific process gases comprising the process gases 110a and / or 110b. For example, modulating the flow rates of the process gases 110a and 110b may include increasing the flow rate of a deposition precursor gas (e.g., trichlorosilane, TCS) contained in the process gases 110a and / or 110b as the first peripheral edge region 192 approaches the region targeted by the angles and orientations of the first and second gas inlets 106a and 106b. Similarly, modulating the flow rates of the process gases 110a and 110b may include increasing the flow rate of an etchant gas (e.g., hydrogen chloride) contained in the process gases 110a and / or 110b as the second peripheral edge region 194 approaches the region targeted by the angles and orientations of the first and second gas inlets 106a and 106b. In this way, the first peripheral edge region 192 is suitably targeted with a larger amount of process gas that deposits epitaxial material on the front surface 142 of the wafer 104 and the second peripheral edge region is suitably targeted with a larger amount of etchant gas that smooths and / or removes epitaxial material deposited on the front surface 142 of the wafer 104.

[0086] Reference Figure 4, a process flow diagram of an example method 200 for processing a semiconductor wafer is shown. Method 200 includes placing 202 a semiconductor wafer 104 in a recess 150 of a carrier 120. Carrier 120 supports wafer 104 within processing environment 102 of heating chamber 100. Recess 150 is defined in front surface 148 of carrier 120 by downwardly depending sidewalls 152. Recess 150 is sized and shaped to receive wafer 104 therein. Preferably, recess 150 is sized and shaped such that peripheral edge 146 of wafer 104 is spaced a distance from sidewalls 152. Due to wafer placement tolerances, movement of the wafer during placement, thermal expansion, and / or other factors, wafer 104 may not be perfectly centered, such that variations in the distance between peripheral edge 146 and sidewalls 152 exist along the circumference of wafer 104.

[0087] Method 200 also includes determining 204 a distance between peripheral edge 146 of wafer 104 and sidewall 152. Suitably, determining 204 includes determining a minimum distance D1 between peripheral edge 146 and sidewall 152 and / or determining a maximum distance D2 between peripheral edge 146 and sidewall 152. The distance between peripheral edge 146 of wafer 104 and sidewall 152 may be determined, for example, by measurements collected by optical sensor 158 (e.g., a camera) as described above. In some examples, method 200 may include determining a peripheral edge region (e.g., region 192) of wafer 104 that is located at a minimum distance D1 from sidewall 152. Additionally or alternatively, method 200 may include determining a peripheral edge region (e.g., region 194) of wafer 104 that is located at a maximum distance D2 from sidewall 152.

[0088] The method 200 also includes supplying 206 a first process gas 110 a into the heating chamber 100 at a first gas flow rate in a first gas direction and supplying 206 a second process gas 110 b into the heating chamber 100 at a second gas flow rate in a second gas direction that intersects the first gas direction. The first process gas 110 a can be supplied by a first gas injection port 106 a and the second process gas 110 b can be supplied by a second gas injection port 106 b. The first and second injection ports 106 a and 106 b can be angled and oriented so that the first and second process gases 110 a and 110 b intersect to create a cross-flow interaction within the processing environment 102, as described above.

[0089] The first process gas 110a may include one or more process gases. For example, the process gas may include a deposition and / or etchant gas, such as used in a selective epitaxial growth process and the like. The first process gas 110a may include one or more deposition precursor gases, and optionally include one or more of a dopant precursor gas, an etchant gas, or a carrier gas. The deposition precursor gas may include a silicon precursor, such as at least one of silane (SiH4), disilane (Si2H6), dichlorosilane (H2SiCl2), and trichlorosilane (HCl3Si). The dopant precursor gas may include at least one of germane (GeH4), phosphine (PH3), diborane (B2H6), arsine (AsH3), or methylsilane (H3CSiH3). The etchant gas may include at least one of methane (CH4), a chloride-containing gas (such as hydrogen chloride (HCl) and / or chlorine (Cl2)), or hydrogen fluoride (HF). The carrier gas may include at least one of nitrogen (N2), argon (Ar), helium (He), or hydrogen (H2).

[0090] To deposit a layer comprising silicon and germanium, the first process gas 110a may include dichlorosilane, germane, diborane, and hydrogen. To deposit a layer of silicon, the first process gas 110a may include at least one of silane, disilane, dichlorosilane, or trichlorosilane, along with hydrogen chloride and hydrogen. To deposit doped silicon, the first process gas 110a may include the aforementioned gases and may further include at least one of phosphine, diborane, or arsine. To deposit a layer comprising silicon and carbon, the first process gas 110a may include at least one of disilane, methylsilane, germane, phosphine, and hydrogen chloride, or chlorine in an environment including at least one of nitrogen or hydrogen.

[0091] The second process gas 110b can be the same as or different from the first process gas 110a. The second process gas 110b can include any or all of the gases discussed above for the first process gas (e.g., a combination of a deposition precursor gas, an etchant gas, a dopant precursor gas, and a carrier gas). For example, during a selective epitaxial growth process, the second process gas 110b can include an etchant gas, a deposition precursor gas, or a combination thereof. The second process gas 110b can flow alternately, periodically, partially simultaneously, or simultaneously with the first process gas 110a.

[0092] For example, the second process gas 110b can be different from the first process gas 110a to improve compositional uniformity in the deposited layer. For example, the second process gas 110b can be different from the first process gas 110a by providing a catalyst gas that catalyzes the first process gas 110a. For example, such catalysis can improve the compositional uniformity and / or thickness of the layer deposited on the wafer 104. The second process gas 110b can include a catalyst and other gases, such as, for example, silane and / or germane, as listed above. An example catalyst can include germane.

[0093] The method 200 also includes supplying 208 heat to the heating chamber 100 to induce deposition of the first process gas 110a and the second process gas 110b on a surface of the wafer 104, such as the front surface 142. The heat may be supplied by radiant heat lamps 128 and / or spot heaters 170, as described above.

[0094] The method 200 further includes modulating 210 a first gas flow rate of the first process gas 110 a, a second gas flow rate of the second process gas 110 b, and / or heat supplied to the heating chamber 100 based on the determined distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 to control a deposition rate of the first process gas 110 a and the second process gas 110 b near the peripheral edge 146 of the wafer 104. Suitably, modulating at least one of the first gas flow rate, the second gas flow rate, and the heat supplied to the heating chamber 100 selectively increases or decreases the deposition rate of the first process gas 110 a and the second process gas 110 b near the peripheral edge 146 of the wafer 104 based on the determined distance between the peripheral edge 146 of the wafer 104 and the sidewall 152.

[0095] For example, the method 200 may include modulating 210 the heat supplied to the heating chamber 100 to increase localized heating within the heating chamber 100 near a first peripheral edge region 192 of the wafer 104 defining a minimum distance D1 from the sidewall 152, and / or modulating the heat supplied to the heating chamber 100 to decrease localized heating within the heating chamber 100 near a second peripheral edge region 194 of the wafer 104 defining a maximum distance D2 from the sidewall. Suitably, modulating 210 the heat supplied to the heating chamber 100 increases the deposition rate of the first and second process gases 110a near the first peripheral edge region 192 and / or decreases the deposition rate of the first and second process gases 110a, 110b near the second peripheral edge region 194. Modulating 210 the heat supplied to the heating chamber 100 may include independently controlling the heat lamps 128 or radial zones thereof, or controlling one or more of the spot heaters 172 to generate radiant heat at a target area on the wafer 104, such as at the peripheral edge region 192. The controller 140 may be used to modulate 210 the heat supplied to the heating chamber 100 by controlling the heating lamps 128 and / or the spot heaters 172 based on the determined 204 distance between the peripheral edge 146 of the wafer 104 and the sidewall 152. In some examples, the method 200 includes rotating the susceptor 120 and the wafer 104 and synchronizing the modulation 210 of the heat supplied to the heating chamber 100 with the rotation of the susceptor 120 and the wafer 104.

[0096] supply Figure 5 and 6To further illustrate, modulating 210 the heat supplied to the heating chamber 100 based on determining 204 a distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 . Figure 5 2 is a diagram illustrating the modulation 210 of localized heating by the spot heater 172 within the heating chamber 100 based on a determined 204 distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 of the carrier 120. Figure 5 As shown in FIG. 1 , localized heating within the heating chamber 100 increases at areas of the wafer 104 near where the distance between the peripheral edge 146 of the wafer and the sidewall 152 of the susceptor 120 is minimized. Figure 6 It is a conceptual depiction of the possibility of modulating 210 as Figure 5 Graph of normalized edge roll-off of epitaxial wafers processed with localized heating as described in FIG. As shown in the figure, compared with the conventional process ( Figure 6 Compared with ERO (POR), the distance 204 is determined based on the Figure 5 middle, Figure 6 The method of modulating 210 localized heating, labeled EOR (New) in FIG, can produce epitaxial wafers with better normalized edge roll-off. This can promote uniformity in thickness and flatness of the epitaxial wafer.

[0097] Reference again Figure 4 The method 200 may additionally and / or alternatively include modulating 210 the first and / or second gas flow rates to achieve a desired flow interaction (e.g., cross-flow interaction) between the first process gas 110a and the second process gas 110b near a peripheral edge region of the wafer 104 based on a determined 204 distance between the peripheral edge 146 and the sidewall 152. The controller 140 may be configured to modulate 210 the first and / or second gas flow rates. For example, the first and / or second gas flow rates may be modulated 210 to increase flow interaction near a first peripheral edge region 192 of the wafer 104 and / or decrease flow interaction near a second peripheral edge region 194 of the wafer 104, where the first process gas 110a and the second process gas 110b comprise a deposition precursor gas. Additionally or alternatively, the first and / or second gas flow rates may be modulated 210 to increase flow interaction near the second peripheral edge region 194 of the wafer 104, where the first process gas 110a and / or the second process gas 110b comprise an etchant gas.

[0098] As described above, the method 200 may also include rotating the carrier 120 and the wafer 104 and modulating 210 the first and / or second gas flow rates in synchronization with the wafer rotation speed to control the deposition rate of the first and second process gases near a target peripheral region of the wafer 104 based on the distance determined 204. For example, as the wafer 104 rotates, the first and / or second gas flow rates may be modulated 210 to increase as the first peripheral edge region 192 approaches a region targeted at the angle and orientation of the first and second gas inlets 106a, 106b and / or the first and / or second gas flow rates may be modulated 210 to decrease as the second peripheral edge region 194 approaches a region targeted at the angle and orientation of the first and second gas inlets 106a, 106b. As described above, modulating 210 the first and / or second gas flow rates may additionally and / or alternatively include modulating 210 the flow rates of specific process gases (e.g., deposition precursor gases and / or etchant gases) including the process gases 110a and / or 110b. The flow rates of particular process gases can be modulated 210 based on the target peripheral edge region of the wafer 104 that experiences the majority of the flow interactions between the first process gas 110a and the second process gas 110b during a particular stage of the deposition process. This can vary as the wafer 104 rotates during processing. Thus, for example, when the first peripheral edge region 192 of the wafer 104 experiences the majority of the flow interactions between the first process gas 110a and the second process gas 110b, the first and / or second gas flow rates can be modulated to increase the flow rate of a deposition precursor gas (e.g., trichlorosilane, TCS). For example, when the second peripheral edge region 194 of the wafer 104 experiences the majority of the flow interactions between the first process gas 110a and the second process gas 110b, the first and / or second gas flow rates can be modulated to increase the flow rate of an etchant gas (e.g., hydrogen chloride, HCl).

[0099] supply Figures 7 to 10 To further illustrate, modulating 210 the first and / or second gas flow rates based on the determined 204 distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 . Figure 7 1 is a graph illustrating modulating 210 the flow rate of trichlorosilane (TCS) process gas within the heating chamber 100 based on a determined 204 distance between the peripheral edge 146 of the wafer 104 and the sidewall 152 of the susceptor 120. Figure 7 As shown in FIG, the flow rate of the TCS process gas increases at an area of ​​the wafer 104 near the location where the distance between the peripheral edge 146 of the wafer and the sidewall 152 of the susceptor 120 is minimum. Figure 8 It is a conceptual depiction of the possibility of modulating 210 as Figure 7 As shown in the figure, compared with the conventional process (in Figure 8Compared with ERO (POR), the distance between Figure 7 In the description, Figure 8 The method of modulating the flow rate of the 210TCS process gas (labeled as EOR (New) in the figure) can produce epitaxial wafers with better normalized edge roll-off. This can lead to better uniformity in the thickness and flatness of the epitaxial circle.

[0100] Figure 9 is a graph illustrating modulation 210 of the flow rate of hydrogen chloride (HCl) process (or etchant) gas flow within the heating chamber 100 based on a determined 204 distance between the peripheral edge 146 of the wafer 104 and the sidewall 152. Figure 9 , the flow rate of the HCl etchant gas increases at an area of ​​the wafer 104 near the location where the distance between the peripheral edge 146 of the wafer and the sidewall 152 of the susceptor 120 is greatest. The flow rate of the HCl etchant gas decreases at an area of ​​the wafer 104 near the location where the distance between the peripheral edge 146 of the wafer and the sidewall 152 of the susceptor 120 is least. Figure 10 is a graph conceptually depicting the normalized edge roll-off of epitaxial wafers processed with or without modulating the flow rate of 210HCl etchant gas, as shown in FIG. Figure 9 As shown in the figure, compared with the conventional process (in Figure 10 Compared with ERO (POR), the distance between Figure 9 In the description, Figure 10 The method of modulating the flow rate of the 210 HCl etchant gas (labeled as EOR (New) in FIG) can produce epitaxial wafers with better normalized edge roll-off. This can lead to better uniformity in thickness and flatness of the epitaxial wafers.

[0101] Described above are example systems and methods for depositing a layer (e.g., an epitaxial layer) onto a semiconductor wafer within a heated chamber, and capable of controlling processing conditions during deposition based on the placement of the wafer within the heated chamber. Specifically, the semiconductor wafer is supported within the heated chamber in a carrier, and the described systems and methods facilitate controlling deposition behavior that would otherwise be affected by the off-center position of the semiconductor wafer within a recess in the carrier. It has been discovered that the distance between the periphery of the wafer and the sidewalls of the recess in the carrier can negatively impact the uniform thickness of the deposited layer and, consequently, the flatness of the processed wafer. Specifically, a greater distance between the peripheral edge of the wafer and the sidewalls of the recess can cause an increase in the thickness of the deposited layer near the peripheral edge of the wafer, while a smaller distance between the peripheral edge of the wafer and the sidewalls can cause a decrease in the thickness of the deposited layer near the peripheral edge of the wafer. Consequently, when the semiconductor wafer is off-center within the recess and the distance between the peripheral edge of the wafer and the sidewalls of the recess varies along the circumference of the wafer, the deposited layer can exhibit increases and decreases near the peripheral edge of the wafer, resulting in non-uniform thickness and poor flatness of the processed wafer. Centering the wafer in the groove is subject to wafer placement tolerances, movement of the wafer during placement, thermal expansion, and / or other limitations, and may not be adequately controlled to mitigate or prevent such deposition behavior near the peripheral edge of the wafer.

[0102] Thus, in the above example, the distance between the peripheral edge of the wafer and the sidewalls of the recess in the carrier is determined, and the process conditions are modulated based on this distance. For example, the flow rate of the process gas introduced into the process environment of the heating chamber and / or the heat supplied to the process environment can be modulated to selectively control the deposition rate at certain peripheral edge regions of the wafer depending on the distance between the peripheral edge and the recess sidewalls. At peripheral regions of the wafer located at a relatively small distance from the recess sidewalls, the process conditions (e.g., process gas flow rate and / or heat intensity) can be modulated to selectively increase the deposition rate at these regions. At peripheral regions of the wafer located at a relatively large distance from the recess sidewalls, the process conditions (e.g., process gas flow rate and / or heat intensity) can be modulated to selectively decrease the deposition rate at these regions. Localized heating control (e.g., using one or more spot heaters) and / or cross-flow interactions between process gases within the process environment can be used to provide greater control over the selective increase and / or decrease in deposition rate at certain peripheral edge regions of the wafer based on their distance from the recess sidewalls. In this way, epitaxial wafers with improved edge roll-off and better thickness uniformity and epitaxial flatness can be produced in a higher throughput and cost-effective manner.

[0103] As used herein, when the terms "about," "substantially," "substantially," and "approximately" are used in conjunction with a range of size, concentration, temperature or other physical or chemical property or characteristic, it is intended to encompass variations that may exist in the upper and / or lower limits of the range for the property or characteristic, including, for example, variations resulting from rounding, measurement method or other statistical variations.

[0104] When introducing elements of the present invention or the embodiments thereof, the articles "a," "an," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0105] As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

1. A method of processing a semiconductor wafer in a heating chamber comprising a carrier for supporting the semiconductor wafer, the carrier having a front surface and a recess in the front surface defined by downwardly depending sidewalls, the method comprising: placing a semiconductor wafer in the recess of the carrier; determining a distance between a peripheral edge of the wafer and the sidewall; supplying a first process gas into the heating chamber in a first gas direction at a first gas flow rate and supplying a second process gas into the heating chamber in a second gas direction intersecting the first gas direction at a second gas flow rate; supplying heat to the heating chamber to induce deposition of the first process gas and the second process gas on a surface of the wafer; and At least one of the first gas flow rate, the second gas flow rate, and the heat supplied to the heating chamber is modulated to control a deposition rate of the first process gas and the second process gas near the peripheral edge of the wafer based on the determined distance between the peripheral edge of the wafer and the sidewall.

2. The method of claim 1, further comprising determining at least one of a minimum distance between the peripheral edge of the wafer and the sidewall and a maximum distance between the peripheral edge of the wafer and the sidewall.

3. The method of claim 2, further comprising modulating the heat supplied to the heating chamber to increase localized heating within the heating chamber near a peripheral edge region of the wafer defining the minimum distance from the sidewall.

4. The method of claim 2, further comprising modulating the heat supplied to the heating chamber to reduce localized heating within the heating chamber near a peripheral edge region of the wafer defining the maximum distance from the sidewall.

5. The method of claim 2 , further comprising modulating at least one of the first gas flow rate and the second gas flow rate to increase flow interaction between the first process gas and the second process gas near a peripheral edge region of the wafer defining the minimum distance from the sidewall.

6. The method of claim 2 , further comprising modulating at least one of the first gas flow rate and the second gas flow rate to reduce flow interaction between the first process gas and the second process gas near a peripheral edge region of the wafer defining the maximum distance from the sidewall.

7. The method according to claim 1 further includes rotating the wafer during the supplying of the first process gas and the second process gas and the supplying of the heat, wherein the modulating at least one of the first gas flow rate, the second gas flow rate, and the heat supplied to the heating chamber is synchronized with a wafer rotation speed to control the deposition rate of the first process gas and the second process gas near the peripheral edge of the wafer based on the determined distance between the peripheral edge of the wafer and the sidewall. 8 . The method of claim 1 , wherein the first process gas and the second process gas comprise a deposition precursor gas and an etchant gas.

9. The method of claim 8, further comprising determining a minimum distance between the peripheral edge of the wafer and the sidewall.

10. The method of claim 9, further comprising modulating at least one of the first gas flow rate and the second gas flow rate to increase the flow of the deposition precursor gas near a peripheral edge region of the wafer defining the minimum distance from the sidewall.

11. The method of claim 9, further comprising modulating at least one of the first gas flow rate and the second gas flow rate to reduce a flow rate of the etchant gas near a peripheral edge region of the wafer defining the minimum distance from the sidewall.

12. The method of claim 1 , wherein modulating at least one of the first gas flow rate, the second gas flow rate, and the heat supplied to the heating chamber selectively increases the deposition rate of the first process gas and the second process gas near a peripheral edge region of the wafer that is a relatively large distance from the sidewall.

13. A method of processing semiconductor wafers in a heated chamber including a carrier for supporting the semiconductor wafers, the carrier having a front surface and a recess defined in the front surface by downwardly depending sidewalls, the method comprising: placing a semiconductor wafer in the recess of the carrier; determining a peripheral edge region of the wafer located at a minimum distance from the sidewall; supplying a first process gas into the heating chamber in a first gas direction at a first gas flow rate and supplying a second process gas into the heating chamber in a second gas direction intersecting the first gas direction at a second gas flow rate; and At least one of the first gas flow rate and the second gas flow rate is modulated to selectively increase a deposition rate of the first process gas and the second process gas near the peripheral edge region of the wafer at the minimum distance from the sidewall. 14 . The method of claim 13 , wherein the first process gas and the second process gas comprise a deposition precursor gas and an etchant gas.

15. The method of claim 14, wherein said modulating said at least one of said first and second gas flow rates comprises increasing a flow rate of said deposition precursor gas near said peripheral edge region of said wafer at said minimum distance from said sidewall.

16. The method of claim 14, wherein said modulating said at least one of said first and second gas flow rates comprises reducing a flow rate of said etchant gas near said peripheral edge region of said wafer at said minimum distance from said sidewall.

17. A method of processing semiconductor wafers in a heated chamber including a carrier for supporting the semiconductor wafers, the carrier having a front surface and a recess defined in the front surface by downwardly depending sidewalls, the method comprising: placing a semiconductor wafer in the recess of the carrier; determining a peripheral edge region of the wafer located at a minimum distance from the sidewall; supplying a process gas into the heating chamber; supplying heat to the heating chamber to induce deposition of the process gas on the surface of the wafer; and The heat supplied to the heating chamber is modulated to selectively increase a deposition rate of the process gas near the peripheral edge region of the wafer at the minimum distance from the sidewall.

18. The method of claim 17, further comprising rotating the susceptor and synchronizing the modulating the heat supplied to the heating chamber with the rotation of the susceptor.

19. The method of claim 17, wherein modulating the heat supplied to the heating chamber comprises selectively increasing localized heating within the heating chamber proximate the peripheral edge region at the minimum distance from the sidewall.

20. The method of claim 17, wherein modulating the heat supplied to the heating chamber comprises modulating one or more spot heaters to selectively increase the localized heating supplied by the one or more spot heaters to the peripheral edge region of the wafer located at the minimum distance from the sidewall.

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