Method for controlling etching depth by local heating

Abstract

Multiple embodiments of the present disclosure relate to a method for controlling the depth of etching by providing local heating on the entire substrate. The method for controlling the temperature on the entire substrate may include individually controlling a plurality of heating cells disposed in a dielectric body of a substrate support assembly. A plurality of heating cells provide a temperature distribution on a first surface of a substrate, and the substrate is disposed on a supporting surface of the dielectric body. The temperature distribution corresponds to a plurality of portions of at least one grating on a second surface of the substrate to be exposed to an ion beam. In addition, the temperature can be controlled by individually controlling the LEDs of a light emitting diode (LED) array. The substrate is exposed to an ion beam to form a plurality of fins on at least one grating. At least one grating has a depth distribution corresponding to the temperature distribution.

Description

background Technical Field

[0002] Various embodiments of the present disclosure are generally directed to methods and systems for controlling etch depth by localized heating. Background Art

[0004] Virtual reality is generally considered to be a computer-generated simulated environment in which the user has a distinct sense of physical presence. The virtual reality experience can be produced in 3D and viewed with a head-mounted display (HMD), such as glasses or other wearable display devices with near-eye display panels as lenses to display the virtual reality environment in place of the actual environment.

[0005] However, augmented reality enables an experience in which the user is still able to see through the display lenses of glasses or other HMD devices to view the surrounding environment, and also to see images of virtual objects generated for display and appearing as part of the environment. Augmented reality can include any type of input, such as audio and tactile input, as well as virtual images, graphics, and video of the environment that can enhance or enhance the user's experience. As an emerging technology, augmented reality presents many challenges and design constraints.

[0006] Virtual images are overlaid on the surrounding environment to provide an augmented reality experience to the user. Waveguides are used to assist in overlaying the image. The generated light propagates through the waveguide until the light exits the waveguide and is overlaid on the surrounding environment. Optical devices typically require multiple waveguides with different physical properties on the same substrate in order to guide different wavelengths of light.

[0007] One challenge with augmented reality is that fabricating waveguides on substrates is a difficult process. It is often difficult to control material properties, such as the temperature of the substrate, which affects the depth profile of the gratings disposed on the substrate. Uncontrolled temperature across the substrate results in an uncontrolled and inconsistent depth profile of the gratings across the substrate.

[0008] Therefore, there is a need for a method to control the etch depth by providing localized heating across the substrate. Summary of the invention

[0009] In one embodiment, a method for controlling temperature across different regions of a substrate includes the following steps: individually controlling a plurality of heating pixels disposed in a dielectric body of a substrate support assembly, the plurality of heating pixels providing a temperature distribution on a first surface of a substrate, the substrate being disposed on a support surface of the dielectric body, the temperature distribution corresponding to a plurality of portions of at least one grating on a second surface of the substrate to be exposed to an ion beam; and exposing the substrate to the ion beam to form a plurality of fins on at least one grating, the at least one grating having a depth distribution corresponding to the temperature distribution, wherein: the temperature distribution includes a first temperature at a first portion of the plurality of portions of the at least one grating, and a second temperature at a second portion of the plurality of portions of the at least one grating; and the first temperature is different from the second temperature.

[0010] In another embodiment, a method for controlling temperature on different regions of an entire substrate includes the following steps: individually controlling LEDs of a light emitting diode (LED) array to provide a temperature distribution on the surface of the substrate, the temperature distribution corresponding to multiple portions of at least one grating on the surface of the substrate to be exposed to an ion beam; and exposing the substrate to the ion beam to form a plurality of fins on at least one grating, the at least one grating having a depth distribution corresponding to the temperature distribution, wherein: the temperature distribution includes a first temperature at a first portion of the multiple portions of the at least one grating and a second temperature at a second portion of the multiple portions of the at least one grating; and the first temperature is different from the second temperature.

[0011] In another embodiment, a method for controlling the temperature on different areas of an entire substrate includes the following steps: individually controlling a plurality of heating cells disposed in a dielectric body of a substrate support assembly, the plurality of heating cells providing a temperature distribution on a first surface of the substrate, the substrate being disposed on a support surface of the dielectric body, the temperature distribution corresponding to a plurality of portions of at least one grating on a second surface of the substrate to be exposed to an ion beam; individually controlling LEDs of a light emitting diode (LED) array to provide a temperature distribution on the second surface of the substrate, the temperature distribution corresponding to a plurality of portions of at least one grating on the surface of the substrate to be exposed to the ion beam; and exposing the substrate to the ion beam to form a plurality of fins on at least one grating, the at least one grating having a depth distribution corresponding to the temperature distribution, wherein: the temperature distribution includes a first temperature at a first portion of the plurality of portions of the at least one grating, and a second temperature at a second portion of the plurality of portions of the at least one grating; and the first temperature is different from the second temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above-mentioned features of the present disclosure can be understood in this manner in detail, and a more specific description of the present disclosure briefly summarized above can be obtained by reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be understood that the drawings illustrate only exemplary embodiments and therefore should not be considered as limiting its scope, and other equally effective embodiments may be recognized.

[0013] Figure 1A is a perspective front view of a substrate having a plurality of lenses arranged on the substrate according to at least one embodiment described herein;

[0014] Figure 1B is a perspective front view of a waveguide combiner according to at least one embodiment described herein;

[0015] Figure 2A is a schematic cross-sectional view of a system including a substrate support assembly and an extraction electrode having an array of light emitting diodes (LEDs) according to at least one embodiment described herein;

[0016] Figure 2B is a perspective front view of a substrate support assembly of a system according to at least one embodiment described herein;

[0017] Figure 2C is a schematic diagram of an LED array of a system according to at least one embodiment described herein;

[0018] Figure 3 is a flow chart of a method of controlling the temperature of different regions of a substrate according to at least one embodiment described herein; and

[0019] Figure 4 is a schematic cross-sectional view of a substrate and a grating according to at least one embodiment described herein.

[0020] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0021] In the following description, several specific details are set forth to provide a more thorough understanding of the embodiments of the present disclosure. However, it will be apparent to those skilled in the art that one or more embodiments of the present disclosure may be performed without one or more of these specific details. In other examples, well-known features are not described in order to avoid making one or more embodiments of the present disclosure confusing.

[0022] Multiple embodiments of the present disclosure generally relate to a method for controlling the depth of etching by providing local heating on the entire substrate. The method for controlling the temperature on different regions of the entire substrate may include: individually controlling a plurality of heating cells disposed in a dielectric body of a substrate support assembly. A plurality of heating cells provide a temperature distribution on a first surface of a substrate, and the substrate is disposed on a supporting surface of the dielectric body. The temperature distribution corresponds to a plurality of portions of at least one grating on a second surface of the substrate to be exposed to an ion beam. In addition, the temperature can be controlled by individually controlling the LEDs of a light emitting diode (LED) array. The substrate is exposed to an ion beam to form a plurality of fins on at least one grating. At least one grating has a depth distribution corresponding to the temperature distribution.

[0023] Figure 1A A perspective front view of a substrate 101 is illustrated according to at least one embodiment. The substrate 101 is configured to be used in an optical device. The substrate 101 can be any substrate used in the art. For example, the substrate 101 includes a semiconductor material such as silicon (Si), germanium (Ge), silicon germanium (SiGe) and / or a III-V semiconductor such as gallium arsenide (GaAs). In another example, the substrate 101 includes a transparent material such as glass and / or plastic. The substrate 101 can have any number of insulating layers, semiconductor layers, or metal layers on the substrate.

[0024] As shown, substrate 101 includes a plurality of lenses 103 disposed on surface 134. Depending on the purpose of substrate 101, the plurality of lenses 103 are configured to focus light. The plurality of lenses 103 are disposed on substrate 101 in a grid of rows and columns. It is contemplated that other suitable arrangements of the plurality of lenses 103 disposed on substrate 101 may be implemented in accordance with the embodiments described herein. Following the method of making a waveguide combiner described herein, individual lenses of the plurality of lenses 103 comprise waveguide combiner 100.

[0025] Figure 1B A perspective front view of a waveguide combiner 100 is illustrated according to one embodiment. The waveguide combiner 100 is configured to guide electromagnetic radiation (e.g., light). As shown, the waveguide combiner 100 includes a plurality of regions, each region including a plurality of gratings 102. The plurality of gratings 102 are configured to receive an incident light beam having an intensity (virtual image) from a microdisplay. Each grating of the plurality of gratings 102 separates the incident light beam into a plurality of modes, each light beam having a mode. The zero-order mode (zero-order mode, T0) light beam is refracted back to the waveguide combiner 100 or is lost in the waveguide combiner 100. The positive first-order mode (T1) light beam passes through the waveguide combiner 100 until the plurality of gratings 102 undergo total internal reflection (TIR). The negative first-order mode (T -1) beam propagates in the waveguide combiner 100 in a direction opposite to that of the T1 beam. -1 The optical beam undergoes TIR through the waveguide combiner 100 .

[0026] Figure 2A is a schematic cross-sectional view of a system 200 according to at least one embodiment of the present invention. The system 200 includes an ion beam chamber 202 equipped with an ion beam source 204 and a substrate support assembly 203 supporting a substrate 101. The substrate support assembly 203 is a pixelated substrate support assembly. The substrate support assembly 203 generally includes a cooling base 220 and a substrate support member, such as an electrostatic chuck 221. The substrate support assembly 203 is removably coupled to the support member 226. The substrate support assembly 203 can be periodically removed from the support member 226 to allow refurbishment of the substrate support assembly 203. The electrostatic chuck 221 generally includes a chucking electrode 218 embedded in a dielectric body 222. The chucking electrode 218 can be configured as a monopole or dipole electrode, or other suitable arrangement. The chucking electrode 218 is coupled to a chucking power supply 230, which provides RF or DC power to electrostatically fix the substrate 101 to the upper surface of the dielectric body 222. The dielectric body 222 may be made of a ceramic material, such as AlN, or a polymer, such as polyimide, polyetheretherketone, polyaryletherketone, and the like.

[0027] The ion beam source 204 is configured to generate an ion beam 206, such as a ribbon beam or a spot beam. The ion beam chamber 202 is configured to direct the ion beam 206 at an optimized angle α relative to a surface normal 223 of the substrate 101. The substrate support assembly 203 includes an electrostatic chuck 221 coupled to a cooling base 220. The cooling base 220 is coupled to a support member 226. In some embodiments, the actuator 208 is configured to tilt the support member 226 so that the substrate 101 is positioned at a tilt angle β relative to the z-axis of the ion beam chamber 202. In another embodiment that may be combined with other embodiments described herein, the actuator 208 rotates the substrate 101 around the x-axis of the support member 226 during operation. In order to form a grating relative to the surface normal 223, the ion beam source 204 generates the ion beam 206, and the ion beam chamber 202 directs the ion beam 206 toward the substrate 101 at an optimized angle α. The actuator 208 positions the support member 226 so that the ion beam 206 contacts the grating material 402 at a desired portion of the grating material 402 at an ion beam angle ( Figure 4 ), and at multiple depths 401 ( Figure 4 ) form a plurality of fins 403.

[0028] System 200 also includes an extraction electrode 236 having a light emitting diode (LED) array 205. Figure 2C As shown in the schematic diagram of the LED array of the system 200, the LED array 205 includes a plurality of individual LEDs 207 arranged in an array of rows and columns. Any number of rows and columns of LEDs 207 may be used. The controller 250 is operable to individually control each of the LEDs 207 of the LED array 205 so that a temperature distribution can be provided on the surface 134 of the substrate 101 facing the ion beam 206 to correspond to at least one of the plurality of gratings 102.

[0029] The substrate support assembly 203 includes a controller 214 operable to communicate with the power source 212, the actuator 208, and a controller 250 of the LED array 205. The controller 214 and the controller 250 are operable to control various aspects of the substrate support assembly 203 during processing. Figure 2A and Figure 2B , an electrostatic chuck 221 includes a plurality of heating cells 216 disposed in a dielectric body 222 and coupled to a power source 228. A controller 214 is operable to individually control each of the heating cells 216 so that a temperature profile can be provided on a surface 132 of a substrate 101 held on a support surface 225 of the dielectric body 222 to correspond to at least one of the plurality of gratings 102. In one embodiment, the heating cells 216 include a plurality of laterally separated heating zones, wherein the controller 214 enables one zone of the heating cells 216 to be preferentially heated relative to one or more other zones. The electrostatic chuck 221 may also include one or more thermocouples (not shown) for providing temperature feedback information to the controller 214 for controlling the power applied to the heating cells 216 by the power source 228, and, as further described below, for operating the cooling base 220.

[0030] The temperature-controlled cooling base 220 is coupled to a heat transfer fluid source 232. The heat transfer fluid source 232 provides a heat transfer fluid, such as a liquid, a gas, or a combination of a liquid and a gas, and the heat transfer fluid is independently circulated near the plurality of heating cells 216, thereby enabling local control of heat transfer between the electrostatic chuck 221 and the cooling base 220, and ultimately controlling the lateral temperature profile of the substrate 101. The fluid distributor 234 is fluidically coupled between the outlet of the heat transfer fluid source 232 and the temperature-controlled cooling base 220. The fluid distributor 234 operates to control the amount of heat transfer fluid provided to the heating cells 216.

[0031] As shown, the controller 214 includes a central processing unit (CPU) 215, a memory 217, and support circuits (or I / O) 219. The CPU 215 is one of any form of computer processors that are used in industrial settings to control various processes and hardware (e.g., pattern generators, motors, and other hardware), and monitor these processes (e.g., process timing and substrate position or location). The memory 217 is connected to the CPU 215 and is one or more of readily available memories, such as random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of digital storage device, whether local or remote. Software instructions and data may be encoded and stored in the memory 217 for instructing the CPU 215. Support circuits 219 are also connected to the CPU 215 for supporting the CPU in a conventional manner. The support circuits 219 include conventional caches, power supplies, clock circuits, input / output circuits, subsystems, and the like.

[0032] As shown, the controller 250 includes a central processing unit (CPU) 291, a memory 293, and support circuits (or I / O) 295. The CPU 291 is one of any form of computer processors that are used in industrial settings to control various processes and hardware (e.g., pattern generators, motors, and other hardware), and monitor these processes (e.g., process timing and substrate position or location). The memory 293 is connected to the CPU 291 and is one or more of readily available memories, such as random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of digital storage device, whether local or remote. Software instructions and data may be encoded and stored in the memory 293 for instructing the CPU 291. Support circuits 295 are also connected to the CPU 291 for supporting the CPU in a conventional manner. The support circuits 295 include conventional caches, power supplies, clock circuits, input / output circuits, subsystems, and the like.

[0033] Figure 3 1-1 is a flow chart of a method 300 for controlling the temperature of different regions of a substrate 101. In these embodiments, FIG. Figure 2C The method 300 is executed by the systems and devices described in the specification, but is not limited to these systems and devices and can be executed by other similar systems and devices.

[0034] In block 302, a plurality of heating cells 216 disposed in a dielectric body 222 of a substrate support assembly 203 are individually controlled. The plurality of heating cells 216 provide a temperature distribution on a surface 132 of a substrate 101 disposed on a support surface 225 of the dielectric body 222. These temperature distributions correspond to a plurality of portions 406 and 408 of the grating 102 on the surface 134 of the substrate 101 to be exposed to the ion beam 206 (see FIG. Figure 4 ).

[0035] In block 304, which may be performed independently or in addition to block 302, LEDs 207 of LED array 205 are individually controlled to provide temperature distributions on surface 134 of substrate 101. These temperature distributions correspond to portions 406 and 408 of grating 102 on surface 134 of substrate 101 to be exposed to ion beam 206 (see Figure 4 ).

[0036] In block 306, the substrate 101 is exposed to the ion beam 206 to form a plurality of fins 403 on the grating 102 having a plurality of depths 401 corresponding to these temperature distributions (see Figure 4 ). The temperature profiles include a first temperature at a first portion 406 of the plurality of portions 405 of the grating 102, and a second temperature at a second portion 408 of the plurality of portions 405 of the grating 102. In these embodiments, the first temperature is different from the second temperature.

[0037] Figure 4 3 is a schematic cross-sectional view of a substrate 101 and a grating 102 before, during, and after a method 300 according to at least one embodiment described herein. In embodiments described herein, when an ion beam 206 is directed toward the substrate 101, the ion beam 206 forms a plurality of fins 403 corresponding to a plurality of depths 401 in a grating material 402 disposed on the lens 103. Figure 4 The ion beam 206 is shown forming a plurality of fins 403 in the grating material 402, but in other embodiments, the plurality of fins 403 may be formed directly on the surface 134 of the substrate 101. The grating material 402 is exposed through a patterned hardmask 404. The plurality of depths 401 of each of the plurality of fins 403 may vary based on the temperature of the substrate 101. As described above, the temperature of the substrate 101 may be controlled by the plurality of heating cells 216 and / or by the LED array 205. Figure 4As shown, the grating 102 can be divided into a plurality of sections 405. The temperature can be controlled in each of the plurality of sections 405 to control the plurality of depths 401. For example, a first temperature can be applied to a first section 406 of the plurality of sections 405 of the grating 102, and a second temperature can be applied to a second section 408 of the plurality of sections 405 of the grating 102. Although Figure 4 Two sections are shown in , but any number of sections in plurality of sections 405 may be used, and any number of different temperatures may be applied to each section in plurality of sections 405 .

[0038] In some embodiments, the grating material 402 includes silicon oxycarbide (SiOC), titanium dioxide (TiO2), silicon dioxide (SiO2), vanadium (IV) oxide (VO x ), aluminum oxide (Al2O3), indium tin oxide (ITO), zinc oxide (ZnO), tantalum pentoxide (Ta2O5), silicon nitride (Si3N4), titanium nitride (TiN) and / or zirconium dioxide (ZrO2). The grating material 402 can have a refractive index between about 1.5 and about 2.65. In some embodiments, the patterned hard mask 404 is a non-transparent hard mask that is removed after forming the waveguide combiner. For example, the non-transparent hard mask includes a reflective material such as chromium (Cr) or silver (Ag). In another embodiment, the patterned hard mask 404 is a transparent hard mask.

[0039] While the foregoing is directed to examples of the present invention, other and further examples of the invention may be devised without departing from the basic scope thereof, and the scope of the invention is determined by the following claims.

Claims

1. A method for controlling the temperature of different regions of a substrate, comprising the following steps: individually controlling a plurality of heating cells disposed in a dielectric body of a substrate support assembly, the plurality of heating cells providing a temperature profile on a first surface of the substrate disposed on a support surface of the dielectric body, the temperature profile corresponding to a plurality of portions of at least one grating on a second surface of the substrate to be exposed to an ion beam; as well as exposing the substrate to the ion beam to form a plurality of fins on the at least one grating, the at least one grating having a depth profile corresponding to the temperature profile, wherein: the temperature profile comprising a first temperature at a first portion of the plurality of portions of the at least one grating, and a second temperature at a second portion of the plurality of portions of the at least one grating; as well as The first temperature is different from the second temperature. The method of claim 1 , wherein at least one lens is disposed on the substrate.

3. The method of claim 2, wherein the at least one grating comprises a grating material. The method of claim 3 , wherein the grating material is exposed through a patterned hard mask.

5. The method of claim 1, wherein the ion beam is configured to be directed to the substrate at an optimized angle relative to a surface normal of the substrate.

6. A method for controlling the temperature of different regions of a substrate, comprising the steps of: individually controlling LEDs of a light emitting diode (LED) array to provide a temperature distribution on the surface of the substrate corresponding to a plurality of portions of at least one grating on the surface of the substrate to be exposed to an ion beam; as well as exposing the substrate to the ion beam to form a plurality of fins on the at least one grating, the at least one grating having a depth profile corresponding to the temperature profile, wherein: the temperature profile comprising a first temperature at a first portion of the plurality of portions of the at least one grating, and a second temperature at a second portion of the plurality of portions of the at least one grating; as well as The first temperature is different from the second temperature. The method of claim 6 , wherein at least one lens is disposed on the substrate.

8. The method of claim 7, wherein the at least one grating comprises a grating material.

9. The method of claim 8, wherein the grating material is exposed through a patterned hard mask.

10. A method for controlling the temperature of different regions across a substrate, comprising the steps of: individually controlling a plurality of heating cells disposed in a dielectric body of a substrate support assembly, the plurality of heating cells providing a temperature profile on a first surface of the substrate disposed on a support surface of the dielectric body, the temperature profile corresponding to a plurality of portions of at least one grating on a second surface of the substrate to be exposed to an ion beam; individually controlling LEDs of a light emitting diode (LED) array to provide a temperature distribution on the second surface of the substrate, the temperature distribution corresponding to a plurality of portions of at least one grating on the surface of the substrate to be exposed to an ion beam; as well as exposing the substrate to the ion beam to form a plurality of fins on the at least one grating, the at least one grating having a depth profile corresponding to the temperature profile, wherein: the temperature profile comprising a first temperature at a first portion of the plurality of portions of the at least one grating, and a second temperature at a second portion of the plurality of portions of the at least one grating; as well as The first temperature is different from the second temperature. The method of claim 10 , wherein at least one lens is disposed on the substrate.

12. The method of claim 11, wherein the at least one grating comprises a grating material.

13. The method of claim 12, wherein the grating material is exposed through a patterned hard mask.

14. The method of claim 10, wherein the ion beam is configured to be directed to the substrate at an optimized angle relative to a surface normal of the substrate.

15. The method of claim 10, further comprising the step of tilting the substrate by an actuator.

16. The method of claim 1, further comprising the step of tilting the substrate by an actuator.

17. The method of claim 1, further comprising the step of rotating the substrate by an actuator.

18. The method of claim 6, further comprising the step of tilting the substrate by an actuator.

19. The method of claim 6, further comprising the step of rotating the substrate by an actuator.

20. The method of claim 10, further comprising the step of rotating the substrate by an actuator.

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