Method for dry etching compound materials

Abstract

A method for processing a substrate is disclosed, the method comprising: receiving a substrate in a vacuum processing chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an interior portion underneath the exposed surface, and one or more of: Al, Ga, In, N, P, As, Sb, Si, or Ge. The method further comprises: altering a chemical composition of the exposed surface and a portion of the interior portion of the III-V film layer using a hydrogen-based plasma treatment to form an altered portion of the III-V film layer; removing the altered portion of the III-V film layer using a chlorine-based plasma treatment; and repeating the altering and removing of the III-V film layer until a predetermined amount of the III-V film layer is removed from the substrate.

Description

[0001] This application claims priority to U.S. Provisional Application No. 62 / 853,458, filed May 28, 2019, and U.S. Application No. 16 / 847,257, filed April 13, 2020, which are hereby incorporated in their entirety by reference. Technical Field

[0002] The present invention generally relates to methods of dry etching, and in specific embodiments, to methods for dry etching compound materials, as well as systems and structures formed therein and utilized therein. Background Technology

[0003] The integrated circuit manufacturing industry has been striving to increase device density to improve speed, performance, and cost. To allow the semiconductor industry to continue scaling to smaller node sizes, device architectures have evolved from two-dimensional (2D) planar structures to include both one-dimensional (1D) and three-dimensional (3D) structures. The technologies required to produce the desired 1D, 2D, and 3D structures—such as nanowires, nanosheets, FinFETs, gate-all-around (GAA) devices, and vertically oriented transistors—are at different stages of development. For example, many processes used to produce complex structures in laboratory or prototyping environments cannot be translated into high-volume manufacturing (HVM).

[0004] As process nodes become smaller, compound materials utilizing two or more elements from Groups III and V of the periodic table can possess desired properties for use in equipment. Fabrication of complex 1D, 2D, and 3D structures can present etching challenges, where both anisotropic and isotropic etching processes are advantageous. However, compound materials can be difficult to etch due to the varying volatility of their constituent elements. Therefore, methods for high-precision etching of compound materials that can be integrated with HVM process flows are likely desirable. Summary of the Invention

[0005] According to one embodiment of the present invention, a method for processing a substrate includes: receiving the substrate in a vacuum processing chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an internal portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge. The method further includes: altering the chemical composition of a portion of the exposed surface and the internal portion of the III-V film layer using hydrogen-based plasma treatment to form the altered portion of the III-V film layer; removing the altered portion of the III-V film layer using chlorine-based plasma treatment; and repeating the alteration and removal of the III-V film layer until a predetermined amount of the III-V film layer is removed from the substrate.

[0006] According to another embodiment of the present invention, a method for processing a substrate includes: receiving the substrate in a vacuum processing chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an inner portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge. The method further includes: treating the exposed surface with a chlorine-based plasma pretreatment to form a passivation layer on the exposed surface; treating the substrate with a hydrogen-based plasma treatment to form a hydrogen interface layer between the passivation layer and the inner portion; removing the passivation layer and the hydrogen interface layer with a chlorine-based plasma treatment to expose the inner portion; and repeating the treatment of the exposed surface, the treatment of the substrate, and the removal of the passivation layer and the hydrogen interface layer until a predetermined amount of the III-V film layer is removed from the substrate.

[0007] According to another embodiment of the present invention, a method for processing a substrate includes: receiving the substrate in a vacuum processing chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an internal portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge. The method further includes: altering the chemical composition of a portion of the exposed surface and the internal portion of the III-V film layer using a hydrogen-based plasma treatment to form the altered portion of the III-V film layer; removing the altered portion of the III-V film layer using a halogen-based plasma treatment; removing halogen-based chemicals from the halogen-based plasma treatment from the vacuum processing chamber; and repeating the alteration of the chemical composition of the exposed surface, the removal of the altered portion of the III-V film layer, and the removal of the halogen-based chemicals from the vacuum processing chamber until a predetermined amount of the III-V film layer is removed from the substrate. Attached Figure Description

[0008] To gain a more complete understanding of the invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0009] Figure 1 Exemplary processes for treating substrates using hydrogen-based plasma processing and halogen-based plasma processing according to embodiments of the present invention are shown.

[0010] Figure 2 An exemplary process for processing a substrate including a substantially anisotropic etching process is shown according to an embodiment of the present invention;

[0011] Figure 3 An exemplary process for processing a substrate including a substantially isotropic etching process is shown according to an embodiment of the present invention;

[0012] Figure 4 A schematic timing diagram illustrating an exemplary method of a process including a substrate processing step according to an embodiment of the present invention is shown.

[0013] Figure 5 Another schematic timing diagram illustrating an exemplary method of a process including a substrate processing step according to an embodiment of the present invention is shown;

[0014] Figure 6 A system for plasma processing according to an embodiment of the present invention is shown;

[0015] Figure 7 An exemplary process for forming a structure according to an embodiment of the present invention is shown;

[0016] Figure 8 An exemplary method including a process for processing a substrate is shown according to an embodiment of the present invention;

[0017] Figure 9 Another exemplary method including a process for processing a substrate, according to embodiments of the present invention, is shown; and

[0018] Figure 10 Another exemplary method including a process for processing a substrate is shown according to an embodiment of the present invention.

[0019] Unless otherwise indicated, corresponding numbers and symbols in the different figures generally refer to corresponding parts. The figures are drawn to clearly illustrate relevant aspects of the embodiments, and these figures are not necessarily drawn to scale. The edges of features drawn in the figures do not necessarily indicate the termination of the feature range. Detailed Implementation

[0020] The following describes in detail the making and use of various embodiments. However, it should be understood that the various embodiments described herein can be applied to a wide variety of specific situations. The specific embodiments discussed are merely illustrative of specific ways of making and using various embodiments and should not be interpreted in a limited manner.

[0021] Many materials considered as novel channel materials for current and future process nodes (e.g., 3nm) are compound materials. In particular, various III-V compounds are being considered. For example, indium gallium arsenide (InGaAs) and other In, Ga, or As-based materials may be desirable as channel materials due to their high electron mobility and other properties.

[0022] However, the volatility of the constituent elements in compound materials varies (e.g., for the same precursors at the same temperature), leading to different relative abilities to be removed from the substrate during etching. The boiling point of the etch product is a good indicator of its volatility. Etching products from In, Ga, and As using halogens such as fluorine (F) and chlorine (Cl) have widely varying boiling points, ranging from -623°C for AsF₂ to 201°C for GaCl₂, and etch products like InCl₂ and InF₂ are practically non-volatile. Increased temperatures are generally not an acceptable solution, as temperatures above around 100°C are not suitable for process integration. Therefore, precise and clean etching of the compound can be challenging.

[0023] Several methods have been used (e.g., in laboratory or small-batch processes) to etch compound materials such as InGaAs. For example, methane (CH4) chemicals (e.g., for non-volatile In species) can be used, but they have the drawback of producing particles deposited on the substrate. Wet removal following oxidation is also possible, but it is not compatible with HVM. Furthermore, profile control can be achieved using silicon (Si) and boron (B) compounds or by passivating the sidewalls, but these carry the well-known and undesirable risk of residue.

[0024] Hydrogen can be used as an etchant for GaAs and InGaAs, but it may disadvantageously require low radio frequency (RF) bias, high hydrogen flux, and may be highly sensitive to crystal defects. Due to the increased reactivity of hydrogen with certain bonds, any defects in the crystal structure can cause surface irregularities such as pitting. Other methods can also be used, combining O2 with Cl2, Cl2 / N2, or CH4 / H2. However, these methods may rely on sidewall passivation to achieve verticality and high RF bias, making them unsuitable for non-destructive processing. Combining halogen etchants with passivation schemes can be generally inflexible (e.g., it cannot easily convert anisotropy to isotropy).

[0025] In various embodiments, a method for treating a substrate that addresses some or all of these drawbacks includes: altering the chemical composition of a portion of the exposed surface and internal portion of a compound material of the substrate using hydrogen-based plasma treatment. The compound material may be a III-V film, for example, comprising one or more of the elements In, Ga, As, aluminum (Al), nitrogen (N), phosphorus (P), or antimony (Sb), as well as other elements such as germanium (Ge) and silicon (Si). The method further includes: removing the altered portion of the compound material using halogen-based plasma treatment. These two steps may be repeated until a predetermined amount of compound material is removed from the substrate.

[0026] The methods described herein can have the advantage of allowing the processing of one or more compound materials, including In, Ga, As, Al, N, P, Sb, Ge, and Si, while maintaining compatibility with HVM processes. These methods can advantageously be dry methods for processing the substrate (i.e., substrate processing that does not expose the substrate to liquids). That is, the methods described herein can advantageously be “all-dry” processes capable of handling the complexities of III-V etching. For example, the methods described herein can advantageously be used in semiconductor device manufacturing, such as during front-end processes (FEOL), mid-end processes (MEOL), logic manufacturing, and memory manufacturing (e.g., NAND memory).

[0027] The hydrogen-based plasma treatment of the embodiments described herein can advantageously utilize hydrogen to weaken bonds. For example, hydrogen can chemically react with compound materials (e.g., GaAs, InGaAs, etc.) and draw electrons, thereby advantageously weakening the lattice. Furthermore, this general process can be advantageously used to adjust the exposure mode of morphological surfaces.

[0028] Another potential benefit of hydrogen-based plasma processing is the ability to achieve orientation control during substrate processing. For example, the pressure during hydrogen-based plasma processing can be controlled to advantageously promote the desired orientation of substrate processing from anisotropic to isotropic. Halogen-based plasma processing can then advantageously maintain the desired orientation.

[0029] A potential advantage of controlling directionality is that halogen-based plasma processing can etch compound materials isotropically, anisotropically, or to any degree in between. The flexibility of etching processes using hydrogen-based and halogen-based plasma processing can advantageously be used to perform substantially anisotropic and substantially isotropic etching using the same chemical substances. Furthermore, etching processes using hydrogen-based and halogen-based plasma processing can advantageously reduce power and / or throughput requirements compared to conventional etching processes.

[0030] Furthermore, the methods described herein can have the advantage of being used to form complex 1D, 2D, and 3D structures. For example, substantially isotropic etching using hydrogen-based plasma processing and halogen-based plasma processing can advantageously undercut structures. Similarly, substantially anisotropic etching using hydrogen-based plasma processing and halogen-based plasma processing can advantageously form recessed regions without sidewall passivation. Substantially isotropic and substantially anisotropic etching can be used alone or in combination to form nanowires, nanosheets, GAA devices, and other complex structures.

[0031] The embodiments provided below describe various methods of dry etching, and in particular embodiments, various methods for dry etching compound materials, as well as the systems and structures utilized therein, are described. The following description describes embodiments. Using Figures 1 to 3 Three embodiments of the substrate processing technology are described. Using... Figure 4 and Figure 5 Two schematic timing diagrams are described. (Using...) Figure 6 An embodiment system for plasma processing is described, while Figures 8 to 10 Three methods are used to describe processes that include treating the substrate.

[0032] Figure 1 Exemplary processes for treating substrates using hydrogen-based plasma processing and halogen-based plasma processing according to embodiments of the present invention are shown.

[0033] See Figure 1 The diagram illustrates a compound material 110 in the initial stage 101 of process 100, which includes an exposed surface 112 and a bottom surface 113. The compound material 110 is included on or within the substrate being processed by process 100. In one embodiment, process 100 is an etching process. As shown, the initial stage 101 may be referred to as the pre-etching stage. The compound material 110 also includes an internal portion 114 located between the exposed surface 112 and the bottom surface 113. In one embodiment, the bottom surface 113 is adjacent to a large portion of the substrate and is not exposed. Alternatively, all or some of the bottom surface 113 may also be exposed (e.g., if the compound material 110 is the entire substrate).

[0034] In various embodiments, compound material 110 may include two or more elements from Group III (also known as “IIIA”, “13”, and “Boron”) and Group V (also known as “VA”, “15”, “Nitrogen Group”, and “Nitrogen Group Elements”) of the periodic table. Compound material 110 may also include additional elements not in Group III or Group V. For example, Si, Ge, etc., may also be included in compound material 110. In various embodiments, compound material 110 is a III-V material, and in some embodiments, it is a III-V film. Alternatively, compound material 110 may also be a III-V wafer. In some embodiments, compound material 110 includes Ga and As. In one embodiment, the compound material is InGaAs. For example, the chemical formula of InGaAs can be written as In x Ga 1-x As, where x is a real number between 0 and 1 (e.g., In). 0.47 Ga 0.53As). Compound material 110 can advantageously possess high electron (or hole) mobility (e.g., for use as a channel material).

[0035] As used herein, the definition of “III-V” is broad and intended to cover materials that include at least one Group III element and at least one Group V element. For example, in the context of this disclosure, binary crystalline compounds that include Group III and Group V elements (e.g., GaAs, InP, InAs, GaSb, InSb, etc.) are III-V materials. Furthermore, in the context of this disclosure, ternary (or higher-order) alloys that include at least one Group III element and at least one Group V element (e.g., InGaAs, GaAsN, GaAsP, InGaAsSb, etc.) are also III-V materials.

[0036] Compound material 110 is shown during hydrogen treatment phase 102, wherein exposed surface 112 is exposed to hydrogen-based plasma treatment 122. For example, hydrogen-based plasma treatment 122 may include hydrogen (H2) plus an inert gas such as Ar. During hydrogen-based plasma treatment 122, a portion 116 of compound material 110 (e.g., a thin surface layer) is implanted with hydrogen. The hydrogen-implanted portion 116 includes some of the exposed surface 112 and internal portions 114.

[0037] Hydrogen-based plasma processing 122 includes hydrogen-based chemical substances 123, which can be free radicals (e.g., H·) or ions (e.g., H2O). + (or mixtures thereof). For example, hydrogen-based chemical 123 may be delivered primarily vertically to exposed surface 112, thereby exposing hydrogen ions on the horizontal surface. Alternatively, hydrogen-based chemical 123 may primarily expose hydrogen radicals on both vertical and horizontal exposed surfaces. The selectivity of treatment may be affected by additional factors such as temperature. In the specific case of InGaAs, the interaction between hydrogen and InGaAs can be controlled by varying the temperature (e.g., below 0°C may be desirable for high aspect ratio structures).

[0038] The diagram illustrates a post-hydrogen treatment stage 103, in which a portion 116 of the compound material 110 has been transformed into the altered portion 118. Specifically, hydrogen-based plasma treatment 122 alters the chemical composition of the exposed surface 112 and the portion 116 of the compound material 110, thereby forming the altered portion 118. In the specific case of InGaAs, hydrogen exposure can transform the crystalline InGaAs structure into InH... x GaH y AsH zThis creates a layer in which the constituent elements are more likely to react with the etchant (e.g., Cl). For example, hydrogen compounds such as arsine, gallane, diethylgallane, and indium can be formed in the modified portion 118. Hydrogen compounds such as these can advantageously weaken the structure of the compound material 110.

[0039] Hydrogen can be considered a weak etchant for many compound materials (e.g., III-V). Therefore, in addition to chemical modification, small amounts of compound material 110 can also be etched away during hydrogen-based plasma treatment 122.

[0040] The substrate processing 100 continues with a halogen treatment stage 104, wherein the exposed surface 112 is exposed to a halogen-based plasma treatment 126. In some embodiments, the halogen-based plasma treatment 126 is a chlorine-based plasma treatment. For example, the halogen-based plasma treatment 126 may include chlorine (Cl2) plus an inert gas such as Ar. The halogen-based chemical 127 included in the halogen-based plasma treatment 126 removes part or all of the altered portion 118, resulting in a post-etch stage 105. The halogen-based chemical 127 includes halogen species (e.g., F, Cl, Br) and may include halogen radicals (e.g., F·, Cl·, Br·) or halide ions (e.g., F2·). - Cl - ,Br - (or both). In some applications (such as front-end processes), chlorine may be advantageous because of its improved process compatibility.

[0041] In some cases, halogen-based plasma treatment 126 can be replaced by different types of plasma treatment. For example, in some embodiments, methane (CH4) can be used as an etchant during treatment stage 104. Alternative treatment options may still preferentially etch the altered portion 118.

[0042] Halogen-based chemical 127 can advantageously remove all elements of the compound material 110 at substantially the same rate, resulting in a smooth etched surface. Furthermore, halogen-based plasma treatment 126 can be selective for the modified portion 118 of the compound material, allowing for improved control over the etching process. The potential benefit of the selectivity of halogen-based plasma treatment 126 is based on the flexibility allowed between anisotropic and isotropic treatments due to the relative exposure of the horizontal and vertical surfaces to hydrogen during hydrogen-based plasma treatment 122.

[0043] The substrate treatment process 100 can be repeated. That is, the post-etching stage 105 can become the initial stage for another iteration of the hydrogen treatment stage 102 and the halogen treatment stage 104. In this way, a precise amount of compound material 110 can be advantageously removed.

[0044] As shown in initial stage 101, an optional halogen-based plasma pretreatment may be performed prior to hydrogen treatment stage 102. For example, the halogen-based plasma pretreatment may be similar to halogen-based plasma treatment 126. An optional passivation layer 33 is formed by exposing an optional exposed surface 35 of the compound material 110 to the optional halogen-based plasma pretreatment. The top surface of the optional passivation layer 33 then serves as the exposed surface 112 for the remainder of process 100 as shown.

[0045] When process 100 includes an optional halogen-based plasma pretreatment, the compound material 110 includes an optional passivation layer 33 formed on an optional exposed surface 35 during the hydrogen treatment stage 102. The exposed surface 112 of the optional passivation layer 33 is exposed to the hydrogen-based plasma treatment 122. An optional hydrogen interface layer 37 is formed by the hydrogen-based plasma treatment 122. It should be noted that process 100, which includes a treatment substrate with an optional halogen-based plasma pretreatment, can also be performed cyclically, but the optional halogen-based plasma pretreatment can be included in each cycle.

[0046] When hydrogen is applied to the optional passivation layer 33, hydrogen species can diffuse into the optional passivation layer 33 and into the compound material 110, thereby forming an optional hydrogen interface layer 37. The hydrogen in the optional hydrogen interface layer 37 can interact with defects in the compound material 110, thereby advantageously resulting in improved surface quality (e.g., smoothness, uniformity, etc.) of the etched surface in the post-etching stage 105. In other words, hydrogen can "fill" defects prior to the etching process, thereby mitigating or eliminating defect formation caused by the etching products.

[0047] In some cases, it may be necessary to address plasma damage. For example, high-energy ions can cause damage during plasma processing. Wet etching techniques can achieve smooth morphologies without damaging the underlying epitaxial growth film (e.g., HF+KMnO). x However, the trade-off is that some etching products (such as InCH) cannot be released. x and InCl x (e.g., indium etching products). Under certain conditions, low-energy ions (e.g., <20V) may be sufficient for indium-containing compound materials. In these cases, InCl may form, and the low pressure can mitigate redeposition.

[0048] Hydrogen-based plasma processing can improve the process by increasing the etching rate, allowing for higher pressures, and preventing defect formation. As an example, when an optional halogen-based plasma pretreatment is included to form an optional passivation layer 33, all processing steps can be performed at high pressures (e.g., >100 mTorr) with zero or low bias. Specifically, the optional halogen-based plasma pretreatment and hydrogen-based plasma treatment 122 can be performed at zero bias (e.g., radical-driven), while the halogen-based plasma treatment 126 can be performed at low bias.

[0049] Figure 2 An exemplary process for processing a substrate including a substantially anisotropic etching process is shown according to an embodiment of the present invention. Figure 2 The process can be other processes described herein (e.g., like...) Figure 1 The specific implementation method of the process. Components with similar markings can be as described previously.

[0050] See Figure 2 The diagram illustrates a compound material 210 at the initial stage 201 of process 200 on a substrate, comprising an exposed surface 212, an internal portion 214, and a bottom surface 213. A masking layer 211 is disposed on the exposed surface 212. It should be noted that, for the sake of brevity and clarity, convention has been used herein and hereinafter to refer to elements x10 adhered to the pattern as relevant implementations of the compound material in various embodiments. Similar conventions have been used for other elements, as explicitly stated by using similar terminology in conjunction with the aforementioned three-digit numbering system.

[0051] Compound material 210 is shown during hydrogen treatment phase 202, wherein exposed surface 212 is exposed to hydrogen-based plasma treatment 222 performed at low pressure. In various embodiments, the hydrogen-based plasma treatment 222 is performed at pressures less than about 30 millitors, and in some embodiments, at pressures between about 3 millitors and about 30 millitors. Due to the low pressure, the hydrogen-based plasma treatment 222 primarily comprises hydrogen ions 223. Hydrogen ions 223 (e.g., H+) + It may advantageously include a non-negligible orientation (e.g., vertical) that promotes preferential exposure of the horizontal surface of the exposed surface 212.

[0052] The masking layer 211 shields the compound material 210 and creates an exposure pattern for hydrogen ions 223. The altered portion 218 is formed from an exposed surface 212 and a portion of an internal portion 214. The altered portion 218 has an altered portion thickness 219, which can depend on the hydrogen diffusivity. In various embodiments, the altered portion thickness 219 is less than about 5 nm, and in some embodiments it is between about 1 nm and about 3 nm. For example, the altered portion thickness 219 can be equal to the thickness of a single layer or several atomic layers of the compound material 210.

[0053] See still Figure 2 The compound material 210 is then shown during halogen treatment stage 204, with exposed surfaces 212 exposed to halogen-based plasma treatment 226. Halogen-based plasma treatment 226 can also be performed at low pressures, but can also be performed at higher temperatures. In various embodiments, halogen-based plasma treatment 226 is performed at pressures less than about 30 millitors, and in some embodiments at pressures between about 3 and about 30 millitors. Alternatively, halogen-based plasma treatment 226 can be performed at pressures greater than 30 millitors.

[0054] As shown in the figure, halogen-based plasma treatment 226 removes all or part of the altered portion 218. Halogen-based plasma treatment 226 includes halogen-based radicals 227 (e.g., Cl·) and / or halogen-based ions 228 (e.g., Cl·). - In one embodiment, the halogen-based plasma treatment 226 is a chlorine-based plasma treatment. Other suitable methods for delivering halogen-based radicals and / or halogen-based ions may also be used.

[0055] Due to the directionality of the hydrogen-based plasma treatment 222, the etching process driven by the halogen-based plasma treatment 226 is advantageously substantially isotropic. That is, process 200 can preferentially etch horizontal surfaces (i.e., lines of sight). For example, the non-horizontal surfaces of the compound material 210 can be etched at a much slower rate (e.g., <5%) compared to horizontal surfaces.

[0056] The rate and quality of the etching process can depend on the selectivity of the halogen-based plasma treatment 226 relative to the modified portion 218 of the compound material 210 (e.g., the remaining internal portion 214). Selectivity can also advantageously self-limit the process 200, thereby allowing for precise removal of the compound material. The removed layer may or may not be a single layer. For example, the removed layer may be several layers. The thickness of the removed layer can depend on the depth of hydrogen penetration during the hydrogen-based plasma treatment 222. The number of modified layers can also vary with dosage (e.g., site density divided by flux, unit reaction probability). Furthermore, the reactivity of the compound material 210 can depend on temperature.

[0057] Figure 3 An exemplary process for processing a substrate including a substantially isotropic etching process is shown according to an embodiment of the present invention. Figure 3 The process can be other processes described herein (e.g., like...) Figure 1 The specific implementation method of the process. Components with similar markings can be as described previously.

[0058] See Figure 3 The diagram shows a compound material 310 in the initial stage 301 of process 300 on a substrate, the compound material comprising an exposed surface 312, an internal portion 314, and a bottom surface 313. A masking layer 311 is disposed on the exposed surface 312. Figure 2 In contrast to process 200, process 300 is radical-driven during the hydrogen treatment stage 302, which advantageously results in substantially isotropic removal of compound material 310, as shown in the figure. Compound material 310 is shown as having had a modified portion of thickness 319 removed prior to the initial stage 301.

[0059] During the hydrogen treatment phase 302, a hydrogen-based plasma treatment 322, including hydrogen-based radicals 323 (e.g., H·), is applied to the exposed surface 312. For example, the hydrogen-based plasma treatment 322 can be performed at high pressure under low bias, zero bias, or reverse bias (e.g., bias that repels hydrogen-based ions). In various embodiments, the hydrogen-based plasma treatment 322 is performed at pressures greater than about 100 millitors.

[0060] It is noteworthy that the non-horizontal surface of compound material 310 is also altered by hydrogen-based radicals 323, as shown in the figure. The lack of directionality provided by the hydrogen-based plasma treatment 322 is likely due to the high-pressure hydrogen-based radicals, which diffuse to the exposed surface with little directionality. Alternatively, non-plasma methods can also be used as hydrogen generators, such as high-pressure microwave hydrogen generators (e.g., remote sources), which can advantageously avoid generating hydrogen-based ions. Furthermore, other suitable methods can be employed to deliver hydrogen-based radicals.

[0061] Similar to Figure 2 The process 200 involves applying a halogen-based plasma treatment 326 to the exposed surface 312 during a halogen treatment stage 304. The resulting removal of the altered portion 318 is advantageously substantially isotropic. For example, the horizontal etching capability provided by substantially isotropic etching can be advantageously applied to manufacturing processes involving nanosheets, nanowires, GAA structures, gate etchback, smaller process nodes (e.g., 3nm), etc.

[0062] In various embodiments, the halogen-based plasma treatment 326 is performed at low pressures (e.g., 3-30 mTorr), but can also be performed at higher pressures. Again, due to the hydrogen-based modification of the compound material 310 during the hydrogen treatment phase 302, process 300 can be self-limiting (e.g., the etch rate of the unmodified compound material is very low, though not zero).

[0063] As previously mentioned, the layer of compound material 310 removed may or may not be a single layer, and can depend on a variety of factors. Halogen-based plasma treatment 326 can utilize mixed plasmas in which ions have a preferred orientation. However, the orientation effect of halogen-based ions 328 can be tuned by fine-tuning process parameters, thereby advantageously improving the approximation or even achieving effective isotropic etching of a truly isotropic etching process.

[0064] Figure 4 A schematic timing diagram illustrating an exemplary method of a process including a substrate processing step according to an embodiment of the present invention is shown. Figure 4 The schematic timing diagram may include the process method, which is another process described herein (e.g., like...). Figure 1 The specific implementation method of the process. Components with similar markings can be as described previously.

[0065] See Figure 4The schematic timing diagram 400 includes alternating phases of a hydrogen-based plasma processing phase 440 and a halogen-based plasma processing phase 445. The hydrogen-based plasma processing phase 440 includes a hydrogen-based plasma processing method as previously described. The hydrogen-based plasma processing phase 440 includes a chemical modification pulse 441 representing a gas flow (e.g., a gas containing a hydrogen-based species). The chemical modification pulse 441 includes a chemical modification pulse duration 442 that is less than or equal to the duration of the hydrogen-based plasma processing phase 440.

[0066] In various embodiments, the chemical modification pulse 441 includes a source power applied to the plasma system to generate plasma. The chemical modification pulse 441 may be or include other applied power (e.g., bias power). For example, the bias power may be a direct current (DC) power source (e.g., continuous, bipolar, etc.). In some embodiments, the chemical modification pulse 441 includes power applied to the plasma system in the range of about 100 W to about 200 W. In one embodiment, the chemical modification pulse 441 includes about 500 W of power applied to the plasma system. However, depending on the specific application, the magnitude of the power applied during the chemical modification pulse 441 may also be other values.

[0067] In various embodiments, the chemical modification pulse 441 includes alternating current (AC) source power, and in some embodiments, it includes radio frequency (RF) source power. In one embodiment, the chemical modification pulse 441 includes high frequency (HF) RF source power. For example, the HF RF source power may be at a frequency of approximately 13.56 MHz. In another embodiment, the chemical modification pulse 441 includes ultra-high frequency (VHF) RF source power. In yet another embodiment, the chemical modification pulse 441 includes ultra-high frequency (UHF) RF source power. However, other frequency ranges may also be used when the chemical modification pulse 441 includes RF source power.

[0068] In some embodiments, the duration of the chemical modification pulse 442 ranges from about 5 s to about 20 s. For example, the duration of the chemical modification pulse 442 can be about 8 s. However, for some applications, the duration of the chemical modification pulse 442 can be greater than 20 s or less than 5 s.

[0069] The chemical modification pulse duration 442 indicates the gas flow during the chemical modification pulse 441. A settling period may exist during the chemical modification pulse 441, during which no power is applied to the plasma system. For example, the settling period may be several seconds. In some embodiments, the chemical modification pulse duration 442 includes a settling period of approximately 3 seconds at the start of the pulse, followed by the application of RF source power for at least 5 seconds. Other combinations of settling and power application may also be utilized.

[0070] The halogen-based plasma treatment phase 445 includes a halogen-based plasma treatment as previously described. The halogen-based plasma treatment phase 445 includes an etching pulse 446 representing a gas flow (e.g., a gas containing a halogen-based species). The gas supplied during the etching pulse 446 is different from the gas of the chemical modification pulse 441. The etching pulse 446 includes an etching pulse duration 447 that is less than or equal to the duration of the halogen-based plasma treatment phase 445. In some cases, a delay may exist between the chemical modification pulse 441 and the subsequent etching pulse, such as for scavenging purposes.

[0071] Similar to the chemical modification pulse 441, the etching pulse 446 may include a source power and / or bias power applied to the plasma system to generate plasma during a portion or all of the halogen-based plasma processing phase 445. The source power applied during the etching pulse 446 may be similar to source powers as previously described, such as being in the range of about 100W to about 200W or about 500W. However, the source power applied during the etching pulse 446 may also have different settings, such as power, frequency, etc. For example, the etching pulse 446 may include an HF RF source power with a frequency of about 27MHz. In other embodiments, the etching pulse 446 may include an RF source power with frequencies in the range of very low frequency (VLF), low frequency (LF), intermediate frequency (MF), etc.

[0072] In some embodiments, the etching pulse duration 447 ranges from about 5 s to about 20 s. For example, the etching pulse duration 447 can be about 8 s. However, for some applications, the etching pulse duration 447 can be greater than 20 s or less than 5 s. The chemical modification pulse duration 442 is not required to be the same as the etching pulse duration 447 and can depend on the specific gas used and the details of a given application. As previously mentioned, a delay may also exist between the etching pulse 446 and the subsequent chemical modification pulse (e.g., for scavenging purposes).

[0073] Figure 5 Another schematic timing diagram illustrating an exemplary method of a process including a substrate processing step according to an embodiment of the present invention is shown. Figure 5 The schematic timing diagram may include the process method, which is another process described herein (e.g., like...). Figure 1 The specific implementation method of the process. Components with similar markings can be as described previously.

[0074] See Figure 5The schematic timing diagram 500 also includes alternating phases of a hydrogen-based plasma processing phase 540 and a halogen-based plasma processing phase 545. The schematic timing diagram 500 can be... Figure 4 The schematic timing diagram 400 is a specific implementation of a purging phase following one or both of the hydrogen-based plasma processing phase and the halogen-based plasma processing phase.

[0075] Specifically, an optional hydrogen-based chemical scavenging stage 543 with a hydrogen-based chemical scavenging duration 544 may be included after the hydrogen-based plasma treatment stage 540. Alternatively or additionally, an optional halogen-based chemical scavenging stage 548 with a halogen-based chemical scavenging duration 549 may be included after the halogen-based plasma treatment stage 545. The optional hydrogen-based chemical scavenging stage 543 can advantageously limit the interaction between hydrogen and etching byproducts. Similarly, the optional halogen-based chemical scavenging stage 548 can advantageously remove etching byproducts and limit / prevent redeposition.

[0076] The removal phase can be symmetrical (i.e., the hydrogen-based chemical removal duration 544 is approximately equal to the halogen-based chemical removal duration 549) or asymmetrical, depending on the desired removal level. In one embodiment, the hydrogen-based chemical removal duration 544 is less than the halogen-based chemical removal duration 549. In various embodiments, the hydrogen-based plasma treatment phase 540 is at least 10 s. In various embodiments, the halogen-based chemical removal duration 549 is also at least 10 s.

[0077] Figure 6 A system for plasma processing according to an embodiment of the present invention is shown. Figure 6 The system can be used, for example, to perform processes and methods as described herein (such as... Figures 1 to 5 The process and / or Figures 8 to 10 Any of the methods. Elements with similar markings may be as previously described.

[0078] See Figure 6The system 600 for plasma processing includes a vacuum processing chamber 52 and a source power coupling element 59. A substrate 50 is disposed within the vacuum processing chamber 52. The vacuum processing chamber 52 may also be referred to as a plasma chamber, processing chamber, or chamber, etc. The substrate 50 can be any suitable material or combination of materials and can be at any stage of processing. In various embodiments, the substrate 50 includes a semiconductor material. The substrate 50 may also include various insulating and / or conductive materials. In various embodiments, the substrate 50 includes a compound material, and in some embodiments includes a III-V material. For example, the substrate 50 may include one or more of InGaAs, GaAs, InP, and other materials.

[0079] Source power coupling element 59 is configured to generate plasma 54 within vacuum processing chamber 52 using source power 63 from source power supply node 65. Plasma 54 is used to process the exposed surface 612 of substrate 50. Specifically, plasma 54 can be used during hydrogen-based and / or halogen-based plasma processing as described herein. Plasma 54 can be any suitable type of plasma. In one embodiment, plasma 54 is surface wave plasma (SWP). Alternatively, plasma 54 can be inductively coupled plasma (ICP), capacitively coupled plasma (CCP), etc. Figure 6 In this context, depending on the stage of the process, plasma 54 indicates both hydrogen-based plasma and halogen-based plasma.

[0080] The gas supplied to the vacuum processing chamber 52 can affect the plasma composition and is therefore different during the two types of plasma processing. For example, during a hydrogen-based plasma processing stage that provides hydrogen-based radicals and / or hydrogen-based ions, a gas (H2) comprising hydrogen-based chemicals can be supplied to the vacuum processing chamber 52. Similarly, a gas comprising halogen-based chemicals (e.g., an etchant source gas, such as Cl2) can be supplied to the vacuum processing chamber 52, thereby directly or indirectly providing halogen-based radicals and / or halogen-based ions through formation within the plasma 54.

[0081] The source power supply node 65 is coupled to ground 60 and also to source power coupling element 59 via source power generator circuit 64. In one embodiment, source power generator circuit 64 provides AC power. For example, the AC power can be any RF power suitable for a frequency (HF, VHF, UHF, MF, LF, VLF, etc.). The vacuum processing chamber 52 may also be grounded (e.g., coupled to ground 60 or a separate ground connection).

[0082] A base chuck 56 is included in a vacuum processing chamber 52. The base chuck 56 is configured to support a base 50 including an exposed surface 612. For example, the exposed surface 612 may be positioned to interact with various species formed by plasma 54. The base chuck 56 may be provided with bias power 68. For example, the base chuck 56 may optionally be coupled to a bias power supply node 67 via a bias power generator circuit 66. The bias power generator circuit 66 may provide, for example, DC-biased AC power. The bias power supply node 67 may also be grounded (e.g., coupled to ground 60 or a separate ground connection).

[0083] Figure 7 An exemplary process for forming a structure according to an embodiment of the present invention is shown. Figure 7 The processes used to form the structure can be combined with the processes, systems and methods described herein (such as... Figures 1 to 5 The process, Figure 6 Systems and / or Figures 8 to 10 Any of the methods. Elements with similar markings may be as previously described.

[0084] See Figure 7 The figure shows a first compound material 710 overlaid on a second compound material 810 at the initial stage 701 of a process 700 for forming a structure. As shown, the first compound material 710 includes a first exposed surface 712. The second compound material 810 may be the entire substrate or may itself be an additional support material overlaid on the substrate.

[0085] In various embodiments, the first compound material 710 and the second compound material 810 are different materials. For example, the first compound material 710 and the second compound material 810 may have different selectivities to various etchants, thereby facilitating selective etching processes. In some embodiments, the first compound material 710 is InGaAs, and in one embodiment it is In... 0.53 Ga 0.47 As. In one embodiment, the second compound material 810 is InP.

[0086] The first compound material 710 can be a semiconductor material. For example, the first compound material 710 can be a doped semiconductor material, and in some embodiments it is a doped III-V material. In applications where the first compound material 710 is a doped semiconductor material, the doped region 717 can have a first doping type (e.g., p-), while the remaining regions of the first compound material 710 have the opposite second doping type (e.g., n+).

[0087] Using dry etching processes (e.g., using a masking layer and...) Figure 2The first exposed surface 712 of the first compound material 710 is anisotropically etched to produce a first post-etch stage 705. In the specific cases of InGaAs and InP, hydrogen-based plasma treatment stages and halogen-based plasma treatment stages (e.g., containing Cl) can be cyclically applied to etch InGaAs. Due to the quasi-self-limiting nature of the etching process, the control over the amount of InGaAs removed can advantageously be high. Therefore, etching can be selective for InGaAs or not; in some cases, a tolerable amount of InP can be etched.

[0088] In the example shown, a portion of the first compound material 710 is removed to form an H-shaped structure having a first end region 71 and a second end region 72 connected by a crossbar 73. The removal of the portion of the first compound material 710 also exposes a second exposed surface 812 of the second compound material 810. At this point, the crossbar 73 of the first compound material 710 is exposed on three faces and includes a doped region 717. A gate electrode can then be formed over the crossbar 73 after the first post-etch stage 705 to form a tri-gate FinFET.

[0089] Alternatively, by combining another etching process, more complex non-planar III-V features can be advantageously formed. For example, horizontal etching (e.g., undercut etching) (such as...) Figure 3 The basically isotropic etching process can be used to form nanosheets, nanowires, GAA structures, gate back etching structures, etc.

[0090] The second exposed surface 812 of the second compound material 810 is etched isotropically using a dry etching process to produce a second post-etch stage 715. The etchant used to etch the second compound material 810 can be highly selective for the second compound material 810 (e.g., the first compound material 710 can be used as a mask). Furthermore, if necessary, a mask layer can be retained to provide further protection for the first compound material 710.

[0091] In specific cases involving InGaAs and InP, hydrogen-based plasma treatment stages and plasma treatment stages (e.g., containing CH4) can be cyclically applied to selectively etch InP. CH4 can etch InP but does not significantly etch InGaAs. In some cases, CH4 can advantageously protect exposed areas of InGaAs (e.g., through monolayer film growth).

[0092] As shown in the figure, the second compound material 810 below the crossbar 73 is etched, causing the crossbar 73 to be suspended, with all four sides exposed. It should be noted that, although not shown for simplicity, the second compound material 810 below the first end region 71 and the second end region 72 may also be partially etched, resulting in a slight overhang of the first compound material 710.

[0093] At this point, a gate material can be formed around the crossbar 73 and patterned to create the gate electrode 79, as shown in device structure 720. The doped region 717 can now be used as a channel 77 of the GAA FET device, with the gate electrode 79 completely surrounding the channel 77 on all four sides. The first end region 71 can then be used as a source / drain region 75, while the second end region serves as a drain / source region 76. Of course, other complex structures besides the GAA FET can also be formed using the methods and processes described herein.

[0094] Process 700 can advantageously utilize compound materials such as III-V materials to generate complex 3D structures. Process 700 can have the advantage of using only dry etching processes that enable process integration (e.g., HVM). Furthermore, III-V materials can be difficult to process using conventional techniques. Due to the ability to use III-V materials in the device, Process 700, as well as other methods and processes described herein, can advantageously achieve smaller process nodes (e.g., 3nm).

[0095] Figure 8 An exemplary method including a process for processing a substrate is shown according to an embodiment of the present invention. Figure 8 The method can be performed using the processes and systems described herein. For example, Figure 8 The method can be with Figures 1 to 7 Any combination of the embodiments. Figure 8 The arrows in the diagram are intended to indicate the order of steps, but are not intended to be restrictive. The method steps described below may be performed in any suitable order as will be apparent to those skilled in the art.

[0096] See Figure 8 The method 800, which includes a process for processing a substrate, includes step 801 of receiving the substrate in a vacuum processing chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an internal portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge.

[0097] Step 802 involves using hydrogen-based plasma treatment to alter the chemical composition of a portion of the exposed surface and the interior of the III-V film layer to form the altered portion of the III-V film layer. Step 803 includes removing the altered portion of the III-V film layer using chlorine-based plasma treatment.

[0098] Method 800 can be performed cyclically. That is, after step 803, method 800 can optionally (and repeatedly) return to step 801, which is indicated as step 804. For example, method 800 can be performed cyclically until the desired amount of the III-V membrane layer has been removed.

[0099] Figure 9 Another exemplary method including a process for processing a substrate is shown according to an embodiment of the present invention. Figure 9 The method can be performed using the processes and systems described herein. For example, Figure 9 The method can be with Figures 1 to 8 Any combination of the embodiments. Figure 9 The arrows in the diagram are intended to indicate the order of steps, but are not intended to be restrictive. The method steps described below may be performed in any suitable order as will be apparent to those skilled in the art.

[0100] See Figure 9 The method 900, which includes a process for processing a substrate, includes step 901 of receiving the substrate in a vacuum processing chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an internal portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge.

[0101] Step 902 includes treating the exposed surface with a chlorine-based plasma pretreatment to form a passivation layer on the exposed surface. Step 903 involves treating the substrate with a hydrogen-based plasma treatment to form a hydrogen interface layer between the passivation layer and the internal portion. Then, in step 904, the passivation layer is removed using a chlorine-based plasma treatment to expose the internal portion.

[0102] Method 900 can be performed cyclically. That is, after step 904, method 900 can optionally (and repeatedly) return to step 901 via step 905. For example, method 900 can be performed cyclically until the desired amount of the III-V membrane layer has been removed.

[0103] Figure 10 Another exemplary method including a process for processing a substrate is shown according to an embodiment of the present invention. Figure 10 The method can be performed using the processes and systems described herein. For example, Figure 10 The method can be with Figures 1 to 9 Any combination of the embodiments. Figure 10 The arrows in the diagram are intended to indicate the order of steps, but are not intended to be restrictive. The method steps described below may be performed in any suitable order as will be apparent to those skilled in the art.

[0104] See Figure 10 The method 1000, which includes a process for processing a substrate, includes step 1001 of receiving the substrate in a vacuum processing chamber. The substrate includes a III-V film layer disposed on the substrate. The III-V film layer includes an exposed surface, an internal portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge.

[0105] Step 1002 involves using hydrogen-based plasma treatment to alter the chemical composition of a portion of the exposed surface and the interior of the III-V film layer to form the altered portion of the III-V film layer. Step 1003 involves using halogen-based plasma treatment to remove the altered portion of the III-V film layer. Step 1004 includes removing halogen-based chemicals from the halogen-based plasma treatment from the vacuum processing chamber.

[0106] Method 1000 can be performed cyclically. That is, after step 1004, method 1000 can optionally (and repeatedly) return to step 1001, which is shown as step 1005. For example, method 1000 can be performed cyclically until the desired amount of the III-V membrane layer has been removed.

[0107] Exemplary embodiments of the invention are summarized herein. Other embodiments may also be understood from the entire specification and from the claims filed herein.

[0108] Example 1. A method for processing a substrate, the method comprising: receiving a substrate in a vacuum processing chamber, the substrate comprising a III-V film layer disposed on the substrate, the III-V film layer comprising an exposed surface, an interior portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge; altering the chemical composition of a portion of the exposed surface and the interior portion of the III-V film layer using hydrogen-based plasma treatment to form an altered portion of the III-V film layer; removing the altered portion of the III-V film layer using chlorine-based plasma treatment; and repeating the alteration and removal of the III-V film layer until a predetermined amount of the III-V film layer is removed from the substrate.

[0109] Example 2. The method as described in Example 1, wherein removing the altered portion comprises substantially anisotropically etching the altered portion of the III-V film.

[0110] Example 3. The method as described in Example 2, wherein the chlorine-based plasma treatment involves a pressure of less than about 30 millitor.

[0111] Example 4. The method as described in Example 1, wherein removing the altered portion comprises etching the altered portion of the III-V film layer substantially isotropically.

[0112] Example 5. The method as described in Example 4, wherein the chlorine-based plasma treatment involves a pressure greater than about 100 millitor.

[0113] Example 6. The method of any one of Examples 1 to 5, wherein the III-V film comprises Ga and As.

[0114] Example 7. The method described in Example 6, wherein the III-V film is InGaAs.

[0115] Example 8. The method of any one of Examples 1 to 7, further comprising: removing chlorine-based chemicals from the chlorine-based plasma treatment from the vacuum processing chamber after the removal of the altered portion and before repeating the alteration and removal.

[0116] Example 9. The method of Example 8, further comprising: after altering the chemical composition of the exposed surface and before removing the altered portion, removing hydrogen-based chemicals from the hydrogen-based plasma treatment from the vacuum treatment chamber, wherein the duration of removing the hydrogen-based chemicals from the vacuum treatment chamber is less than the duration of removing the chlorine-based chemicals from the vacuum treatment chamber.

[0117] Example 10. The method as described in any of Examples 1 to 10, wherein the altered portion of the III-V film is less than about 5 nm.

[0118] Example 11. A method for processing a substrate, the method comprising: receiving a substrate in a vacuum processing chamber, the substrate including a III-V film layer disposed on the substrate, the III-V film layer including an exposed surface, an interior portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge; treating the exposed surface using a chlorine-based plasma pretreatment to form a passivation layer on the exposed surface; treating the substrate using a hydrogen-based plasma treatment to form a hydrogen interface layer between the passivation layer and the interior portion; removing the passivation layer and the hydrogen interface layer using a chlorine-based plasma treatment to expose the interior portion; and repeating the treatment of the exposed surface, the treatment of the substrate, and the removal of the passivation layer and the hydrogen interface layer until a predetermined amount of the III-V film layer is removed from the substrate.

[0119] Example 12. The method as described in Example 11, wherein the chlorine-based plasma treatment includes a pressure greater than about 100 millitor.

[0120] Example 13. The method as described in one of Examples 11 and 12, wherein the III-V film comprises Ga and As.

[0121] Example 14. The method as described in Example 13, wherein the III-V film is InGaAs.

[0122] Example 15. The method of one of Examples 11 to 14, wherein: no bias power is applied to the substrate during the chlorine-based plasma pretreatment and the hydrogen-based plasma treatment; and both the chlorine-based plasma pretreatment and the hydrogen-based plasma treatment involve pressures greater than about 100 millitors.

[0123] Example 16. The method of Example 15, further comprising: applying a bias power between about 100 W and about 200 W to the substrate during the chlorine-based plasma treatment; and wherein the chlorine-based plasma treatment includes a pressure greater than about 100 millitor.

[0124] Example 17. A method for processing a substrate, the method comprising: receiving a substrate in a vacuum processing chamber, the substrate including a III-V film layer disposed on the substrate, the III-V film layer including an exposed surface, an interior portion below the exposed surface, and one or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge; altering the chemical composition of a portion of the exposed surface and the interior portion of the III-V film layer using a hydrogen-based plasma treatment to form an altered portion of the III-V film layer; removing the altered portion of the III-V film layer using a halogen-based plasma treatment; removing halogen-based chemicals from the halogen-based plasma treatment from the vacuum processing chamber; and repeating the alteration of the chemical composition of the exposed surface, the removal of the altered portion of the III-V film layer, and the removal of the halogen-based chemicals from the vacuum processing chamber until a predetermined amount of the III-V film layer is removed from the substrate.

[0125] Example 18. The method as described in Example 17, wherein the III-V film comprises Ga and As.

[0126] Example 19. A method as described in one of Examples 17 and 18, wherein the halogen-based plasma treatment is a chlorine-based plasma treatment, and the halogen-based chemical is a chlorine-based chemical.

[0127] Example 20. The method of one of Examples 17 to 19, further comprising: removing hydrogen-based chemicals from the hydrogen-based plasma treatment from the vacuum treatment chamber after altering the chemical composition of the exposed surface and before removing the altered portion.

[0128] Although the invention has been described with reference to illustrative embodiments, this description is not intended to be limiting. Various modifications and combinations of the illustrative embodiments and other embodiments of the invention will be apparent to those skilled in the art from the description. Therefore, it is intended that the appended claims cover any such modifications or embodiments.

Claims

1. A method for processing a substrate, the method comprising: A substrate is received in a vacuum processing chamber, the substrate comprising a III-V film layer disposed on the substrate, the III-V film layer comprising... Exposed surfaces, The internal portion beneath the exposed surface, and One or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge; The chemical composition of the exposed surface and a portion of the interior of the III-V film is altered using hydrogen-based plasma treatment to form the altered portion of the III-V film. The altered portion of the III-V film was removed using chlorine-based plasma treatment; as well as Repeat this alteration and removal of the III-V membrane until a predetermined amount of the III-V membrane is removed from the substrate.

2. The method of claim 1, wherein removing the altered portion comprises anisotropically etching the altered portion of the III-V film.

3. The method of claim 2, wherein the chlorine-based plasma treatment comprises a pressure of less than 30 millitor.

4. The method of claim 1, wherein removing the altered portion comprises isotropically etching the altered portion of the III-V film.

5. The method of claim 4, wherein the chlorine-based plasma treatment comprises a pressure greater than 100 millitor.

6. The method of claim 1, wherein the III-V film comprises Ga and As.

7. The method of claim 6, wherein the III-V film is InGaAs.

8. The method of claim 1, further comprising: After the altered portion is removed and before the alteration and removal are repeated, the chlorine-based chemicals from the chlorine-based plasma treatment are removed from the vacuum processing chamber.

9. The method of claim 8, further comprising: After altering the chemical composition of the exposed surface and before removing the altered portion, hydrogen-based chemicals from the hydrogen-based plasma treatment are removed from the vacuum treatment chamber, wherein the duration of removal of the hydrogen-based chemicals from the vacuum treatment chamber is less than the duration of removal of the chlorine-based chemicals from the vacuum treatment chamber.

10. The method of claim 1, wherein the altered portion of the III-V film is less than 5 nm.

11. A method for processing a substrate, the method comprising: A substrate is received in a vacuum processing chamber, the substrate comprising a III-V film layer disposed on the substrate, the III-V film layer comprising... Exposed surfaces, The internal portion beneath the exposed surface, and One or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge; The exposed surface is treated with chlorine-based plasma pretreatment to form a passivation layer on the exposed surface; The substrate is treated with hydrogen-based plasma processing to form a hydrogen interface layer between the passivation layer and the internal portion; The passivation layer and the hydrogen interface layer are removed using a chlorine-based plasma treatment to expose the internal portion; as well as Repeat the treatment of the exposed surface, the treatment of the substrate, and the removal of the passivation layer and the hydrogen interface layer until a predetermined amount of the III-V film layer is removed from the substrate.

12. The method of claim 11, wherein the chlorine-based plasma treatment comprises a pressure greater than 100 millitor.

13. The method of claim 11, wherein the III-V film comprises Ga and As.

14. The method of claim 13, wherein the III-V film is InGaAs.

15. The method of claim 11, wherein: No bias power is applied to the substrate during the chlorine-based plasma pretreatment and the hydrogen-based plasma treatment.

16. The method of claim 15, wherein both the chlorine-based plasma pretreatment and the hydrogen-based plasma treatment comprise a pressure greater than 100 millitor.

17. The method of claim 16, further comprising: During the chlorine-based plasma treatment, a bias power between 100W and 200W is applied to the substrate.

18. The method of claim 17, wherein the chlorine-based plasma treatment comprises a pressure greater than 100 millitor.

19. A method for processing a substrate, the method comprising: A substrate is received in a vacuum processing chamber, the substrate comprising a III-V film layer disposed on the substrate, the III-V film layer comprising... Exposed surfaces, The internal portion beneath the exposed surface, and One or more of the following: Al, Ga, In, N, P, As, Sb, Si, or Ge; The chemical composition of the exposed surface and a portion of the interior of the III-V film is altered using hydrogen-based plasma treatment to form the altered portion of the III-V film. The altered portion of the III-V film was removed using halogen-based plasma treatment; The halogen-based chemicals from the halogen-based plasma treatment are removed from the vacuum processing chamber; as well as The alteration of the chemical composition of the exposed surface, the removal of the altered portion of the III-V film, and the removal of the halogen-based chemical from the vacuum processing chamber are repeated until a predetermined amount of the III-V film is removed from the substrate.

20. The method of claim 19, wherein the III-V film comprises Ga and As.

21. The method of claim 19, wherein the halogen-based plasma treatment is a chlorine-based plasma treatment, and the halogen-based chemical substance is a chlorine-based chemical substance.

22. The method of claim 19, further comprising: After altering the chemical composition of the exposed surface and before removing the altered portion, the hydrogen-based chemicals from the hydrogen-based plasma treatment are removed from the vacuum processing chamber.

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