Directed deposition on patterned structures

Abstract

The present invention relates to directional deposition on patterned structures. The present invention provides methods and related devices for facilitating patterning by performing highly non-conformal (directional) deposition on patterned structures. The method includes depositing a film on a patterned structure (e.g., a hard mask). The deposition can be substrate selective, so that the film has a high etch selectivity relative to the underlying material to be etched, and is pattern selective, so that the film is directionally deposited to replicate the pattern of the patterned structure. In some embodiments, the deposition is performed in the same chamber as the chamber in which subsequent etching is performed. In some embodiments, the deposition can be performed in a separate chamber (e.g., a PECVD deposition chamber) connected to the etching chamber by a vacuum transfer chamber. The deposition can be performed before or during a selected interval during the etching process. In some embodiments, the deposition involves multiple cycles of the deposition process and the treatment process.

Description

[0001] This application is a divisional application of the invention patent application with application number 201611177683.3, application date December 19, 2016, applicant is Rum Research Company, and invention name is "Directed deposition on patterned structures". Technical Field

[0002] The present invention relates generally to the field of semiconductors and, more particularly, to directional deposition on patterned structures. Background Art

[0003] In the scaling of 3D-NAND and DRAM, up to 64 pairs of ONON / OPOP are used for channel holes. One of the key challenges in etching these high aspect ratio holes is the mask loss during etching. The typical mask selectivity is in the range of 5-8 times the etching selectivity, which results in the need for a mask height in the range of 0.5 to 2 microns, depending on the depth of the hole. A taller mask increases the aspect ratio of the hole, thereby increasing the difficulty of etching. The increasing plasma density and ion energy used to etch these high aspect ratio holes reduces the efficiency of the conventional practice of slowing down mask corrosion by non-selectively depositing fluorocarbon-based polymers during etching. Summary of the invention

[0004] The present invention provides methods and apparatus for directional deposition on patterned structures. In some embodiments, the method involves performing a multi-cycle directional deposition process to deposit a mask building material on the patterned structure. Each cycle can include (i) depositing a first material on the patterned structure by a plasma enhanced chemical vapor deposition (PECVD) process, and (ii) plasma treating the first material to improve directionality.

[0005] According to various embodiments, the first material can be a silicon-based material, a carbon-based material, a boron-based material, or a combination thereof. In some embodiments, the first material includes two or more of silicon, carbon, boron, phosphorus, arsenic, and sulfur. In some embodiments, the first material is a metal-containing material. In some embodiments, the plasma treatment includes exposing the first material to a nitrogen-based plasma, an oxygen-based plasma, a hydrogen-based plasma, a hydrocarbon-based plasma, an argon-based plasma, a helium-based plasma, or a combination thereof.

[0006] In some embodiments, the method includes etching a layer masked by a patterned structure. The patterned structure may include a raised feature having a feature top and a feature sidewall. In such embodiments, processing the first material may include redepositing the first material from the feature sidewall to the feature top.

[0007] In some embodiments, each cycle includes reacting the first material to form the second material. In some embodiments, each cycle includes changing the material property of the first material. For example, changing the material property of the first material may include one or more of plasma treatment, exposure to ultraviolet radiation, or thermal annealing.

[0008] In some embodiments, deposition by PECVD process comprises introducing a silicon-containing precursor, a carbon-containing precursor, a boron-containing precursor or a metal-containing precursor into a plasma reactor. In some embodiments, deposition by PECVD process comprises introducing a silicon-containing precursor selected from silane, halogenated silane, organosilane or aminosilane.

[0009] In some embodiments, deposition by a PECVD process includes introducing a silicon-containing precursor selected from the group consisting of methylsilane, ethylsilane, isopropylsilane, tert-butylsilane, dimethylsilane, diethylsilane, di-tert-butylsilane, allylsilane, sec-butylsilane, thexylsilane, isopentylsilane, tert-butyldisilane, di-tert-butyldisilane, tetrachlorosilane, trichlorosilane, dichlorosilane, monochlorosilane, chloroallylsilane, Silane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, tert-butylchlorosilane, di-tert-butylchlorosilane, chloroisopropylsilane, chlorosec-butylsilane, tert-butyldimethylchlorosilane, tert-hexyldimethylchlorosilane, monoaminosilane, diaminosilane, triaminosilane, tetraaminosilane, tert-butylaminosilane, methylaminosilane, tert-butylsilylamine, bis(tert-butylamino)silane or tert-butyl silylcarbamate.

[0010] In some embodiments, the deposition by PECVD process includes introducing a gas selected from methane (CH4), acetylene (C2H2), ethylene (C2H4), propylene (C3H6), butane (C4H 10 ), cyclohexane (C6H 12 ), benzene (C6H6) and toluene (C7H8).

[0011] In some embodiments, deposition by a PECVD process includes introducing a boron-containing precursor selected from borane (BH3), diborane (B2H6), and triborane (B3H7).

[0012] In some embodiments, deposition by a PECVD process includes introducing a metal-containing precursor selected from penta(dimethylamido)tantalum, trimethylaluminum, tetraethoxytitanium, tetrakis-dimethylamidotitanium, tetrakis(ethylmethylamido)hafnium, bis(cyclopentadienyl)manganese, and bis(n-propylcyclopentadienyl)magnesium.

[0013] In some embodiments, one or both of the PECVD process and the plasma treatment operation uses an inductively coupled plasma, or a capacitively coupled plasma, or a microwave plasma. In some embodiments, one or both of the PECVD process and the plasma treatment operation uses a direct plasma, or a remote plasma, or a combination thereof. In some embodiments, one or both of the PECVD process and the plasma treatment operation is an ion-assisted process, or a free radical-assisted process, or a combination thereof.

[0014] Also provided is an apparatus for performing the method disclosed herein. The apparatus may include one or more processing chambers, such as an inductively coupled etch chamber or a capacitively coupled etch chamber, and a controller having machine-readable instructions for performing the method.

[0015] Specifically, some aspects of the present invention can be described as follows:

[0016] 1. A method comprising:

[0017] A multi-cycle directional deposition process is performed to deposit a mask building material on the patterned structure, wherein each cycle comprises:

[0018] i) depositing a first material on the patterned structure by a plasma enhanced chemical vapor deposition (PECVD) process, and

[0019] ii) plasma treating the first material to improve directionality.

[0020] 2. The method of clause 1, wherein the first material is a silicon-based material, a carbon-based material, a boron-based material, or a combination thereof.

[0021] 3. The method of clause 1, wherein the first material comprises two or more of silicon, carbon, boron, phosphorus, arsenic, and sulfur.

[0022] 4. The method of clause 1, wherein the first material is a metal-containing material.

[0023] 5. The method of clause 1, wherein (ii) comprises exposing the first material to a nitrogen-based plasma, an oxygen-based plasma, a hydrogen-based plasma, a hydrocarbon-based plasma, an argon-based plasma, a helium-based plasma, or a combination thereof.

[0024] 6. The method of clause 1, wherein (ii) comprises exposing the first material to a plasma generated from a hydrogen-containing compound.

[0025] 7. The method according to clause 5, wherein the hydrogen-containing compound is one of H2, CH4, NH3, C2H2 and N2H2.

[0026] 8. The method of clause 1, further comprising etching a layer masked by the patterned structure.

[0027] 9. The method of clause 1, wherein the patterned structure comprises a raised feature having a feature top and a feature sidewall.

[0028] 10. The method of clause 9, wherein processing the first material comprises redepositing the first material from the feature sidewalls to the feature top.

[0029] 11. The method of clause 1, wherein each cycle further comprises reacting the first material to form a second material.

[0030] 12. The method of clause 1, wherein each cycle further comprises changing a material property of the first material.

[0031] 13. The method of clause 12, wherein said changing a material property of said first material comprises one or more of plasma treatment, exposure to ultraviolet radiation, or thermal annealing.

[0032] 14. The method of clause 1, wherein depositing by the PECVD process comprises introducing a silicon-containing precursor, a carbon-containing precursor, a boron-containing precursor, or a metal-containing precursor into a plasma reactor.

[0033] 15. The method of clause 14, wherein depositing by the PECVD process comprises introducing a silicon-containing precursor selected from the group consisting of silanes, halogenated silanes, organosilanes, or aminosilanes.

[0034] 16. The method of clause 14, wherein the deposition by the PECVD process comprises introducing a silicon-containing precursor selected from the group consisting of methylsilane, ethylsilane, isopropylsilane, tert-butylsilane, dimethylsilane, diethylsilane, di-tert-butylsilane, allylsilane, sec-butylsilane, tert-hexylsilane, isopentylsilane, tert-butyldisilane, di-tert-butyldisilane, tetrachlorosilane, trichlorosilane, dichlorosilane, monochlorosilane, chlorosilane, Allylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, tert-butylchlorosilane, di-tert-butylchlorosilane, chloroisopropylsilane, chlorosec-butylsilane, tert-butyldimethylchlorosilane, tert-hexyldimethylchlorosilane, monoaminosilane, diaminosilane, triaminosilane, tetraaminosilane, tert-butylaminosilane, methylaminosilane, tert-butylsilylamine, bis(tert-butylamino)silane or tert-butyl silylcarbamate.

[0035] 17. The method of clause 14, wherein the deposition by the PECVD process comprises introducing a gas selected from methane (CH4), acetylene (C2H2), ethylene (C2H4), propylene (C3H6), butane (C4H 10 ), cyclohexane C6H 12 ), benzene (C6H6) and toluene (C7H8).

[0036] 18. The method of clause 14, wherein depositing by the PECVD process comprises introducing a boron-containing precursor selected from borane (BH3), diborane (B2H6), and triborane (B3H7).

[0037] 19. The method of clause 14, wherein deposition by the PECVD process comprises introducing a metal-containing precursor selected from the group consisting of penta(dimethylamido)tantalum, trimethylaluminum, tetraethoxytitanium, tetrakis-dimethylamidotitanium, tetrakis(ethylmethylamido)hafnium, bis(cyclopentadienyl)manganese, and bis(n-propylcyclopentadienyl)magnesium.

[0038] 20. The method of clause 1, wherein one or both of the PECVD process and the plasma treatment operation uses an inductively coupled plasma, or a capacitively coupled plasma, or a microwave plasma.

[0039] 21. The method of clause 1, wherein one or both of the PECVD process and the plasma treatment operation uses a direct plasma, or a remote plasma, or a combination thereof.

[0040] 22. The method of clause 1, wherein one or both of the PECVD process and the plasma treatment operation is an ion-assisted process, or a radical-assisted process, or a combination thereof.

[0041] 23. An apparatus comprising:

[0042] a chamber configured to hold a substrate;

[0043] a plasma generator integrated with or connected to the chamber; and

[0044] A controller comprising instructions for performing a multi-cycle directional deposition process to deposit a mask building material on a patterned structure, wherein the instructions include:

[0045] i) instructions for depositing a first material on the patterned structure by a plasma enhanced chemical vapor deposition (PECVD) process, and

[0046] ii) instructions for plasma treating the first material to improve directionality.

[0047] These and other aspects are further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Operations of an example of an integrated process including directional deposition on a hard mask are shown.

[0049] Figure 2 Certain operations in an example of a method of directional deposition on high aspect ratio features are shown.

[0050] Figure 3a-3d Schematic examples of three high aspect ratio patterned hard mask features during a directional deposition process are shown.

[0051] Figure 4 Certain operations in an example of a method of directional deposition on high aspect ratio features are shown.

[0052] Figure 5 and Figure 6 is a schematic diagram of an example of a process chamber for performing the method according to the disclosed embodiments. DETAILED DESCRIPTION

[0053] In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments presented. The disclosed embodiments may be practiced without some or all of these specific details. In other cases, well-known process operations are not described in detail to avoid unnecessarily obscuring the disclosed embodiments. Although the disclosed embodiments will be described in conjunction with specific embodiments, it should be understood that they are not intended to limit the disclosed embodiments.

[0054] In semiconductor processing, masking methods are used to pattern and etch substrates. Mask loss during etching (also known as mask erosion) is a key challenge in etching high aspect ratio features (such as holes and trenches). Provided herein is a method for depositing a film on a mask or on a substrate pattern. The deposition can be substrate selective (so that the film has high etching selectivity relative to the substrate) and pattern selective (so that the film is directional deposited on the pattern and replicates the pattern). The deposited material is called a mask building material. In some embodiments, the deposition is performed in the same chamber as the chamber in which the etching is performed, also known as in-situ deposition. In some embodiments, the deposition can be performed in a separate chamber (e.g., a PECVD chamber or a different etching chamber) connected to the main etching chamber by a transfer chamber. It should be noted that although the description mainly relates to deposition on a patterned hard mask, the method disclosed herein includes directional deposition on any patterned structure to replicate the structural pattern.

[0055] Deposition of the mask building material may be performed prior to or at selected intervals during the etching process. Figure 1Operations of an example of an integrated process including directional deposition on a hard mask are shown. Figure 1 In , at 10, a hard mask 105 and a photoresist 109 are formed on the material to be etched 101. The hard mask 105 can be any suitable material, including an organic or inorganic hard mask. Examples of organic hard masks include doped or undoped amorphous carbon (also known as ashable hard mask or AHM) and organosiloxane materials. Examples of inorganic hard mask materials include polycrystalline silicon and amorphous silicon (poly-Si, a-Si), silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbonitride (SiCN), titanium nitride (TiN), tungsten (W) and other metals that can be selectively removed after feature etching. The hard mask can be doped, an example being a boron-doped AHM. In some embodiments, the hard mask may be a metal hard mask (MHM), examples of which include metals such as aluminum (Al), metal nitrides such as TiN and tantalum nitride (TaN), tungsten (W), and metal oxides such as aluminum oxide (Al2O3). In some embodiments, the hard mask may be a ceramic hard mask (CHM).

[0056] The process then proceeds to photoresist development (20) and hard mask opening (30) to expose the material to be etched. Figure 1 In the example of , before etching material 101, mask building material 111 is directionally deposited on hard mask 105 to increase the aspect ratio of the patterned features of hard mask 105. See operation 40. This allows the subsequent etching to proceed longer to provide a deeper etch. Material 101 is then etched. See operation 50. Figure 1 In the example of , the mask building material 111 is completely removed during etching. However, in some embodiments, some of it may remain. At operation 50, if etching is complete, the hard mask 105 can be removed by an appropriate process. However, in some embodiments, an on-pattern directional deposition of mask building material can be performed after 50 to increase the aspect ratio of the patterned features of the hard mask before continuing the etching process. The eroded mask material can be restored with the same or similar material or a different material and restored to the same or different profile as desired.

[0057] Figure 2 Certain operations in a method of directional deposition on high aspect ratio features are shown. As described above, directional deposition can be performed in an etch chamber before or in the middle of an etch process to increase the aspect ratio of a mask covering the material to be etched.

[0058] exist Figure 2In the process of depositing a mask building material on the high aspect ratio features by a plasma enhanced chemical vapor deposition (PECVD) process. See box 201. The mask building material is typically different from the mask material, can be deposited by PECVD, and has at least some etch selectivity to the material to be etched. Therefore, the mask building material will depend on the material to be etched and the etching chemistry to be used. Typically, the mask building material is a dielectric material. Examples include silicon-containing films and carbon-containing films and combinations thereof.

[0059] To promote directional deposition, in some embodiments, the deposition chemistry may include molecules with a high sticking coefficient and a low mobility. The sticking coefficient is the ratio of the number of adsorbed molecules that adhere to the surface to the total number of molecules that strike the surface during the same time period. The sticking coefficient depends on the size (large molecules have a higher sticking coefficient) and the propensity to adsorb on the surface.

[0060] Mobility refers to the surface and gas diffusion rate of a molecule. In some embodiments, a deposition chemistry comprising polymer chains can be used. Such chains can be formed in a plasma during a PECVD process. For example, chlorosilanes with hydrogen (H2) can be introduced into a chamber. The plasma can be excited to produce free radicals (denoted by a*) and ions, and subsequent reactions produce chlorinated polysilanes.

[0061] Examples of plasma reactions include:

[0062] H2+e - →2H*+e -

[0063] SiCl4+e - →SiCl3+Cl*+e -

[0064] SiCl4+H*→SiCl3*+HCl

[0065] SiCl4+2H*→HSiCl3+HCl

[0066] SiCl3*+2H*→SiCl2*+HCl+H*,

[0067] or →HSiCl2*+Cl*+H*,

[0068] or →HSiCl3+H*,

[0069] or →H2SiCl*+2Cl*,

[0070] n(SiCl2*)+mSiCl3*→Si2Cl6+…→Si3Cl8+…→Si n Cl 2n+2

[0071] n(HSiCl*)+mH2SiCl*→H2Si2Cl4+→H x Si n Cl 2n+2-x

[0072] Similar reactions also occur on the surface, further complicating the deposition process.

[0073] Chloropolysilanes can be large clusters. Both chlorosilanes and chlorinated polysilanes have high adhesion coefficients and low mobility, which helps provide directional deposition on the pattern. Other exemplary deposition chemistries are discussed further below. After block 201, the mask building material deposited on the high aspect ratio features can be directionally deposited, with the deposited material being thicker at the top of the feature than along the sidewalls and at the bottom of the feature. Figure 3a Schematic illustration of a high aspect ratio patterned hard mask feature following block 201 is shown. Figure 3a In the example of , patterned hard mask features 303 are shown covering material to be etched 309. Patterned hard mask features 303 can be characterized as having feature tops 305 and sidewalls 307. Patterned hard mask features 303 form high aspect ratio holes 313, which can be, for example, contact holes or trenches. Bottom 311 of hole 313 can be referred to as feature bottom.

[0074] In some embodiments, a bias voltage is applied to the wafer during PECVD deposition. This can increase the sticking coefficient of various species in the plasma. For example, the bias voltage can increase the sticking coefficient of chlorosilane ion groups.

[0075] Plasma 301 generated in a gas mixture containing a silicon precursor and a diluent gas is used to deposit a silicon film on the hard mask. Exemplary plasma species include SiH y Cl x * radicals 302, H* atoms 308, and chlorinated polysilane 306. Hydrogen chloride (HCl) species 304 are generated as a byproduct. The silicon-containing species deposits silicon build material 312 on the patterned hard mask features 303. Figure 3a In the example of , deposition is directional because more build material 312 is deposited on the feature top 305 than on the sidewalls 307 and bottom 311. The thickness of build material 312 decreases as the depth of the feature increases.

[0076] Back to Figure 2 , and then treating the deposited mask building material to enhance directionality. See box 203. Enhancing directionality can increase the aspect ratio of the mask building material. In some embodiments, the mask building material is no more than a few nanometers thick on the sidewalls of the patterned hard mask. Directivity can also be characterized by top:bottom step coverage or top:sidewall step coverage. Figure 3d, for example, 320 represents the top thickness, 322 represents the bottom thickness, and 324 represents the sidewall thickness. Step coverage is the ratio of two thicknesses, for example, top:bottom step coverage or top:sidewall step coverage. When measuring the sidewall thickness, the thickness at the midpoint of the feature depth can be used. In some embodiments, the processing operation increases the top:bottom step coverage or the top:sidewall step coverage. In some embodiments, block 203 also modifies the material properties (e.g., density, chemical composition, or etch resistivity) of the deposited material.

[0077] Operation 203 may include exposing the mask building material to a plasma species having high mobility and capable of etching the mask building material. The plasma species may chemically etch the mask building material selectively relative to the material to be etched and / or relative to the hard mask. In some embodiments, the reaction product of the chemical etching is redeposited as a building material on an upper portion of the patterned hard mask features.

[0078] In some embodiments, a hydrogen-based plasma is used. A hydrogen-based plasma is a plasma in which hydrogen species (primarily H radicals) are the primary processing species and may be the primary etching species in some embodiments. In some embodiments, a hydrogen-based plasma may be formed from a gas consisting essentially of H2. In some embodiments, one or more inert gases may be present with the H2. A hydrogen-based plasma may selectively etch silicon without etching oxides.

[0079] In some embodiments, a plasma generating gas including one or more of the following is introduced into a plasma generator to generate plasma species. In some embodiments, the plasma generating gas includes one or more hydrogen-containing plasmas. Examples of such gases include H2, CH4, NH3, C2H2, and N2H2. The resulting plasma can be a hydrogen-based plasma.

[0080] In some embodiments, nitrogen-based plasma, oxygen-based plasma, hydrocarbon-based plasma, argon-based plasma, or helium-based plasma may be used. In nitrogen-based plasma, the main process species is nitrogen, in oxygen-based plasma, the main process species is oxygen, and so on. In some embodiments, these may be the main etching species for processes involving etching.

[0081] Figure 3b An illustrative example of a high aspect ratio patterned hard mask feature after block 203 is shown. The treatment plasma 321 may include, for example, one or more of Ar ions, Si ions, H* atoms, N ions, and Cl* atoms. Ultraviolet light generated from the plasma or from a separate UV source may also be in the chamber.

[0082] exist Figure 3b In FIG. 3 , the treatment plasma includes H* atoms 308, N ions 309, and Ar ions 310. These can penetrate deep into the holes 313 and etch the build material 312 from the sidewalls 307 and bottom 311 of the feature. Some of the etched build material can be redeposited at the top 305 of the feature. Various product species 315 can form and cause redeposition or leave as byproducts. Examples of product species can include SiCl x H y Substance, Si x H y and N x H y In this way, the directionality of the mask build material is improved toward the top of the patterned hard mask features compared to toward the sidewalls and bottom. Figure 2 , blocks 201 and 203 may be repeated one or more times to achieve the desired aspect ratio. Block 201 may be performed only long enough to deposit only a thin layer of mask building material on the sidewalls and bottom of the feature so that it can be removed in block 203. An exemplary top thickness for each cycle may be to or to within the range. Figure 3c Schematic examples of hardmask and mask building materials patterned in the Nth and (N+1)th cycles are shown.

[0083] Figure 4 Certain operations in a method of directional deposition on high aspect ratio features are shown. As described above, directional deposition can occur in an etch chamber prior to an etch process or in the middle of an etch process to increase the aspect ratio of a mask covering the material to be etched. Figure 4 The process described in is similar to that described in Figure 2 The process described herein, wherein operations 201 and 203 are performed as described above. However, in Figure 4 In an example, after the deposited material is treated to increase the pattern selectivity, the mask building material can react to increase the etch selectivity. See block 204. In one example, the silicon mask building material can be exposed to a carbon-containing gas to form silicon carbide. This is particularly useful for forming a mask building material with high etch selectivity to oxides. In other examples, the silicon mask building material can be exposed to a nitrogen-containing gas to form silicon nitride.

[0084] In some embodiments, Figure 4Operation 204 in the embodiment may be performed before operation 203, so that the mask building material reacts to form another material before the processing. In some embodiments, operation 204 may be performed only after multiple cycles of operations 203 and 204. For example, operation 204 may be performed after operation 205.

[0085] In some embodiments, Figure 2 Operation 203 or Figure 4 An optional densification operation is performed after operation 204 in . If performed, the densification operation may involve, for example, thermal annealing, exposure to ultraviolet radiation, or plasma densification treatment. In some embodiments, the Figure 2 or Figure 4 An optional densification operation is performed after operation 205 in. In some embodiments, operations 203 and 204 can be performed simultaneously using appropriate chemicals.

[0086] During deposition and processing, process conditions are adjusted to provide non-conformal deposition without pinch-off. Pinch-off refers to the growth of adjacent features together to pinch off the area between the features. As discussed further below based on experimental results, various process conditions can be adjusted to provide directional deposition during PECVD deposition, as well as to provide improved directionality and vertical sidewalls during processing operations. Cycling (rather than continuous PECVD) and using processing operations have been shown to contribute to well-defined high aspect ratio build material features in some embodiments. The bias voltage during PECVD deposition can also increase non-conformality and reduce pinch-off. The residence time (flow rate) and plasma power during deposition also affect non-conformality and pinch-off. Adding additive gases during processing operations can help prevent etching of previously deposited materials at the top of the features. The plasma power and exposure time during processing can also be adjusted to limit etching of the hard mask walls and bottom.

[0087] Although the above discussion focuses on depositing silicon-based mask building materials, other materials may be used, such as carbon films. When depositing silicon, any suitable silicon-containing precursor may be used, including silanes (e.g., SiH4), polysilanes (H3Si-(SiH2) n-SiH3) (where n>1), organosilanes, halosilanes and aminosilanes. Organosilanes such as methylsilane, ethylsilane, isopropylsilane, tert-butylsilane, dimethylsilane, diethylsilane, di-tert-butylsilane, allylsilane, sec-butylsilane, tert-hexylsilane, isopentylsilane, tert-butyldisilane, di-tert-butyldisilane, etc. can be used. Halogenated silanes contain at least one halogen group and may or may not contain hydrogen and / or carbon groups. Examples of halosilanes are iodosilanes, bromosilanes, chlorosilanes and fluorosilanes. Specific chlorosilanes are tetrachlorosilane (SiCl4), trichlorosilane (HSiCl3), dichlorosilane (H2SiCl2), monochlorosilane (ClSiH3), chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, tert-butylchlorosilane, di-tert-butylchlorosilane, chloroisopropylsilane, chlorosec-butylsilane, tert-butyldimethylchlorosilane, tert-butyldimethylchlorosilane, etc. Aminosilanes include at least one nitrogen atom bonded to a silicon atom, but may also contain hydrogen, oxygen, halogens and carbon. Examples of aminosilanes are monoaminosilane, diaminosilane, triaminosilane and tetraaminosilane (H3Si(NH2)4, H2Si(NH2)2, HSi(NH2)3 and Si(NH2)4, respectively), and substituted monoaminosilanes, diaminosilanes, triaminosilanes and tetraaminosilanes, such as tert-butylaminosilane, methylaminosilane, tert-butylsilylamine, bis(tert-butylamino)silane (SiH2(NHC(CH3)3)2(BTBAS)), tert-butyl silylcarbamate, SiH(CH3)-(N(CH3)2)2, SiHCl-(N(CH3)2)2, (Si(CH3)2NH)3, and the like.

[0088] The deposited films are typically amorphous and the film composition will depend on the specific precursors and co-reactants used, with organosilanes leading to a-SiC:H films, while aminosilanes will lead to a-SiN:H or a-SiCN:H films.

[0089] In depositing the carbon film, any suitable carbon-containing precursor may be used. In some embodiments, a precursor having the formula C x H y wherein X is an integer between 2 and 10 and Y is an integer between 2 and 24. Examples include methane (CH4), acetylene (C2H2), ethylene (C2H4), propylene (C3H6), butane (C4H 10 ), cyclohexane (C6H 12 ), benzene (C6H6) and toluene (C7H8).

[0090] In some embodiments, the construction material may be doped or include materials such as boron or phosphorus. Additional dopants include arsenic, sulfur, and selenium. In this way, the etching selectivity to the underlying film may be improved. For example, for doped dielectrics (particularly silicon dioxide-based dielectrics), the process gas may include a dopant precursor, such as a boron-containing gas, a phosphorus-containing gas, a carbon-containing gas, or a mixture thereof. In a specific embodiment, the gas comprises one or more boron-containing reactants and one or more phosphorus-containing reactants, and the dielectric film comprises phosphorus-doped and boron-doped silica glass (BPSG). Examples of suitable boron precursor gases and phosphorus precursor gases include borane (BH3), diborane (B2H6), triborane (B3H7), and phosphine (PH3). Examples of arsenic-containing gases, sulfur-containing gases, and selenium-containing gases include hydrogen selenide (H2Se), arsine (AsH3), and hydrogen sulfide (H2S).

[0091] If the dielectric is to contain oxynitride (eg, silicon oxynitride), the deposition gas may include nitrogen-containing reactants such as N2, NH3, NO, N2O, and mixtures thereof. Examples of deposited films include silicon doped with boron, silicon boride, silicon carbon boride, and the like.

[0092] Metal-containing films can also be deposited. Examples of metal-containing films that can be formed include oxides and nitrides of aluminum, titanium, hafnium, tantalum, tungsten, manganese, magnesium, strontium, etc., and elemental metal films. Exemplary precursors can include metal alkylamines, metal alkoxides, metal alkylamides, metal halides, metal β-diketonates, metal carbonyl compounds, organometallic compounds, etc. Suitable metal-containing precursors will include metals that are desired to be incorporated into the film. For example, a tantalum-containing layer can be deposited by reacting five (dimethylamido) tantalum with ammonia or another reducing agent as an auxiliary reactant. Other examples of usable metal-containing precursors include trimethylaluminum, tetraethoxytitanium, tetra-dimethyl-amido titanium, tetra(ethylmethylamide) hafnium, bis(cyclopentadienyl) manganese, and bis(n-propylcyclopentadienyl) magnesium, etc.

[0093] Examples of the process chemistry include nitrogen-containing process chemistry, oxygen-containing process chemistry, carbon-containing process chemistry, and halogen-containing process chemistry, as well as inert gas, in addition to hydrogen.

[0094] In some embodiments, blocks 203 and 204 may be combined. For example, operations may include exposing the deposited material to a hydrogen-containing compound, such as CH4, NH3, H2Se, H2S, AsH3, or PH3, to simultaneously treat and react the deposited material.

[0095] Device

[0096] In some embodiments, the directional deposition is performed in an etching apparatus. For example, the above method can be performed in an inductively coupled plasma etching apparatus or a capacitively coupled plasma etching apparatus.

[0097] Figure 5 A cross-sectional view of an inductively coupled plasma etching apparatus 500 is schematically shown according to some embodiments herein. The Kiyo TM Reactor is an example of a suitable reactor that can be used to implement the technology described herein. The inductively coupled plasma etching device 500 includes a total processing chamber that is structurally defined by a chamber wall 501 and a window 511. The chamber wall 501 can be made of stainless steel or aluminum. The window 511 can be made of quartz or other dielectric materials. The optional internal plasma grid 550 divides the total etching chamber into an upper sub-chamber 502 and a lower sub-chamber 503. In most embodiments, the plasma grid 550 can be removed, thereby utilizing the chamber space made by the sub-chambers 502 and 503. The chuck 517 is positioned in the lower sub-chamber 503 near the bottom inner surface. The chuck 517 is configured to receive and hold a semiconductor wafer 519 on which an etching process is performed. The chuck 517 can be an electrostatic chuck for supporting the wafer 519 when the wafer 519 is present. In some embodiments, an edge ring (not shown) surrounds the chuck 517 and has an upper surface that is substantially in the same plane as the top surface of the wafer 519 (when the wafer is present above the chuck 517). The chuck 517 also includes electrostatic electrodes for clamping and releasing the wafer. A filter and a DC clamp power source (not shown) may be provided for this purpose. Other control systems may also be provided for lifting the wafer 519 off the chuck 517. The chuck 517 may be charged with an RF power source 523. The RF power source 523 is connected to a matching circuit 521 via a connector 527. The matching circuit 521 is connected to the chuck 517 via a connector 525. In this way, the RF power source 523 is connected to the chuck 517.

[0098] The coil 533 is located above the window 511. The coil 533 is made of a conductive material and includes at least one full turn. Figure 5The exemplary coil 533 shown in includes three turns. The cross-section of the coil 533 is shown with symbols, and the coil 533 with an "X" extends rotationally into the page, while the coil 533 with a "●" extends rotationally out of the page. The RF power source 541 is configured to provide RF power to the coil 533. Generally, the RF power source 541 is connected to the matching circuit 539 via a connector 545. The matching circuit 539 is connected to the coil 533 via a connector 543. In this way, the RF power source 541 is connected to the coil 533. An optional Faraday shield 549 is positioned between the coil 533 and the window 511. The Faraday shield 549 is maintained in a spaced relationship relative to the coil 533. The Faraday shield 549 is disposed directly above the window 511. The coil 533, the Faraday shield 549 and the window 511 are each configured to be substantially parallel to each other. The Faraday shield can prevent metal or other substances from being deposited on the dielectric window of the plasma chamber.

[0099] The process gas may be supplied through the main injection port 560 located in the upper chamber and / or through the side injection port 570, sometimes referred to as STG. During an operational plasma process, a vacuum pump (e.g., a one-stage or two-stage dry mechanical pump and / or turbomolecular pump 540) may be used to draw the process gas from the process chamber 524 and maintain the pressure within the process chamber 500 by using a closed loop controlled flow restriction device such as a throttle valve (not shown) or a pendulum valve (not shown).

[0100] During operation of the device, one or more reactant gases may be supplied through injection ports 560 and / or 570. In certain embodiments, the gas may be supplied only through the main injection port 560, or only through the side injection port 570. In some cases, the injection port may be replaced by a showerhead. The Faraday shield 549 and / or the optional grid 550 may include internal passages and holes that enable process gases to be delivered to the chamber. One or both of the Faraday shield 549 and the optional grid 550 may serve as a showerhead for delivering process gases.

[0101] RF power is supplied from RF power source 541 to coil 533 to cause RF current to flow through coil 533. The RF current flowing through coil 533 generates an electromagnetic field around coil 533. The electromagnetic field generates an induced current within upper sub-chamber 502. During the etching process, the physical and chemical interactions of the generated various ions and radicals with wafer 519 selectively etch features on the wafer.

[0102] If a plasma grid is used so that both the upper sub-chamber 502 and the lower sub-chamber 503 exist, the induced current acts on the gas present in the upper sub-chamber 502 to produce an electron-ion plasma in the upper sub-chamber 502. The optional internal plasma grid 550 limits the amount of hot electrons in the lower sub-chamber 503. In some embodiments, the device is designed and operated so that the plasma present in the lower sub-chamber 503 is an ion-ion plasma.

[0103] Both the upper electron-ion plasma and the lower ion-ion plasma may contain cations and anions, although the ion-ion plasma will have a greater ratio of anions:cations. Volatile etching byproducts may be removed from the lower sub-chamber 503 through port 522.

[0104] The disclosed chuck 517 can operate in an elevated temperature range between about 30° C. and about 250° C. The temperature will depend on the etching process operation and the specific recipe. In some embodiments, the chamber 501 can also operate at a pressure in a range between about 1 mTorr and about 95 mTorr. In certain embodiments, the pressure can be higher, as disclosed above.

[0105] Chamber 501 can be coupled to a facility (not shown) when the facility is installed in a clean room or manufacturing plant. The facility includes piping that provides process gases, vacuum, temperature control, and environmental particle control. These facilities are coupled to chamber 501 when installed in the target manufacturing plant. In addition, chamber 501 can be coupled to a transfer chamber, allowing semiconductor wafers to be transferred in and out of chamber 501 by a robot using typical automation.

[0106] In some embodiments, a system controller 530 (which may include one or more physical or logical controllers) controls some or all operations of the etch chamber. The controllers are further described below.

[0107] Figure 6 600 is a schematic diagram of an example of a capacitively coupled plasma etching apparatus according to various embodiments. The plasma etching chamber 600 includes an upper electrode 602 and a lower electrode 604, between which a plasma can be generated. A substrate 699 having a patterned hard mask thereon and as described above can be placed on the lower electrode 604 and can be fixed in place by an electrostatic chuck (ESC). Other clamping mechanisms can also be used. The plasma etching chamber 600 can include a plasma confinement ring 606, which maintains the plasma above the substrate and away from the chamber wall. Other plasma confinement structures can be used, such as a shield that acts as an inner wall. In some embodiments, the plasma etching chamber may not include any such plasma confinement structures.

[0108] exist Figure 6In the embodiment of the present invention, the plasma etching chamber 600 includes two RF sources, an RF source 610 connected to the upper electrode 602 and an RF source 612 connected to the lower electrode 604. Each of the RF sources 610 and 612 may include one or more sources of any suitable frequency, including 2 MHz, 13.56 MHz, 27 MHz, and 60 MHz. Gases may be introduced into the chamber from one or more gas sources 614, 616, and 618. For example, the gas source 614 may include a deposition gas and an etching gas as described above. Gases may be introduced into the chamber through an inlet 620, and excess gas and reaction byproducts may be discharged via an exhaust pump 622.

[0109] An example of a plasma etch chamber that may be used is available from Lam Research Corp. of Fremont, California, USA. Flex TM Reactive Ion Etching Tools. Further description of plasma etch chambers may be found in U.S. Patent Nos. 6,841,943 and 8,552,334, the entire contents of which are incorporated herein by reference.

[0110] Back to Figure 6 , controller 530 is connected to RF sources 610 and 612 and valves associated with gas sources 614, 616, and 618, and exhaust pump 622. In some embodiments, controller 530 controls all activities of plasma etching chamber 600.

[0111] The following discussion of controller 530 may be applied to Figure 5 and Figure 6 Controller 530 in. Controller 530 may execute control software stored in a mass storage device, loaded into a memory device, and executed on a processor. Alternatively, the control logic may be hard-coded in controller 530. Alternatively, the control logic may be hard-coded in controller 530. Application specific integrated circuits, programmable logic devices (e.g., field programmable gate arrays, or FPGAs), etc. may be used for these purposes. In the following discussion and in Figure 6 In the discussion of controllers in , wherever the term "software" or "code" is used, functionally equivalent hard-coded logic can be used in its place.

[0112] The control software may include instructions for controlling the timing and / or magnitude of application of any one or more of the following chamber operating conditions: mixture and / or composition of gases, chamber pressure, chamber temperature, wafer temperature / wafer support temperature, bias applied to the wafer, frequency and power applied to coils or other plasma generating components, wafer position, wafer movement speed, and other parameters of a particular process performed by the tool. The control software may be configured in any suitable manner. For example, various process tool component subroutines or control objects may be written to control the operation of process tool components required to perform various process tool processes. The control software may be encoded in any suitable computer readable programming language.

[0113] In some embodiments, the control software may include input / output control (IOC) sequencing instructions for controlling the various parameters described above. Other computer software and / or programs stored on a mass storage device and / or memory device associated with the controller 530 may be employed in some embodiments. Examples of programs or portions of programs used for this purpose include process gas control programs, pressure control programs, and RF source control programs.

[0114] The process gas control program may include code for controlling gas composition (e.g., deposition gases and process gases as described herein) and flow rates, and optionally for flowing gases into the chamber to stabilize the pressure in the chamber prior to etching. The pressure control program may include code for controlling the pressure in the chamber by adjusting, for example, a throttle valve in the exhaust system of the chamber, the gas flowing into the chamber, etc. The RF source control program may include code for setting the RF power level applied to the electrode according to embodiments of the present invention.

[0115] In some embodiments, there may be a user interface associated with the system controller 530. The user interface may include a display screen, a graphical software display of apparatus and / or process conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, and the like.

[0116] In some embodiments, the parameters adjusted by the system controller 530 may relate to process conditions. Non-limiting examples include process gas composition and flow rate, temperature, pressure, plasma conditions (e.g., RF bias power level), pressure, temperature, etc. These parameters may be provided to the user in the form of a recipe, which may be entered using the user interface.

[0117] Signals for monitoring the process can be provided from various process tool sensors through analog and / or digital input connections of the system controller 530. Signals for controlling the process can be output through analog and digital output connections of the plasma etch chamber. Non-limiting examples of sensors that can be monitored include mass flow controllers, pressure sensors (e.g., manometers), thermocouples, and the like. Appropriately programmed feedback and control algorithms can be used with data from these sensors to maintain process conditions.

[0118] The system controller 530 may provide program instructions for performing the above-described directional deposition process and subsequent etching process. The program instructions may control various process parameters, such as RF bias power level, pressure, temperature, etc. The instructions may control these parameters to directional deposit mask building films according to various embodiments described herein.

[0119] The controller 530 will typically include one or more memory devices and one or more processors configured to execute instructions so that the apparatus will perform methods according to the embodiments disclosed herein. For example, as described above, a machine-readable medium containing instructions for controlling process operations according to the embodiments disclosed herein may be coupled to the controller 530.

[0120] In some implementations, the controller 530 may be part of or form part of a system controller that is part of a system that may be part of the above examples. Such a system may include a semiconductor processing device that includes one or more processing tools, one or more processing chambers, one or more platforms for processing, and / or dedicated processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronic devices for controlling their operation before, during, and after processing semiconductor wafers or substrates. The electronic device may be referred to as a "controller" that may control various components or subcomponents of one or more systems. Depending on the processing conditions and / or the type of system, the system controller may be programmed to control any of the processes disclosed herein, including controlling process gas delivery, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer in and out tools and other transfer tools and / or load locks connected to or interfaced with a dedicated system.

[0121] Broadly speaking, a system controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions may be instructions that are transmitted to the system controller in the form of various individual settings (or program files) that define operating parameters for performing specific processing on or for a semiconductor wafer or system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer for completing one or more processing steps during the preparation of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0122] In some implementations, the system controller may be part of or coupled to a computer that is integrated with, coupled to, or connected to the system or a combination thereof via a network. For example, the system controller may be in the "cloud" or may be all or part of a wafer fab host system that may allow remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, check the history of past manufacturing operations, check trends or performance criteria for multiple manufacturing operations, change parameters of a current process, set processing steps to follow the current process, or start a new process. In some instances, a remote computer (e.g., a server) may provide a process recipe to the system via a network that may include a local network or the Internet. The remote computer may include a user interface that allows input or programming of parameters and / or settings, which are then transmitted from the remote computer to the system. In some instances, the system controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be for the type of process to be performed and the type of tool to which the system controller is configured to connect or control the tool type. Thus, as described above, the system controller may be distributed, for example, by including one or more discrete controllers that are networked together and work toward a common goal (e.g., the process and control provided by the present invention). Examples of distributed controllers for these purposes may be one or more integrated circuits on a chamber that communicate with one or more remote integrated circuits (e.g., at the platform level or as part of a remote computer), which combine to control the process within the chamber.

[0123] In some embodiments, PECVD deposition may employ a remote free radical assisted plasma or microwave plasma. Such deposition may be performed in an etching chamber equipped with a remote plasma generator or microwave plasma generator, or may be performed in a deposition chamber connected to the etching chamber under vacuum. Similarly, in some embodiments, a remote free radical assisted plasma or microwave plasma may be used to perform the processing operation.

[0124] Exemplary process parameters are given below. Exemplary pressure ranges are 5 mT to 1000 mT, and in some embodiments, between 40 mT to 100 mT. In processing operations, exemplary pressures may be in the range of 5 mT to 300 mT.

[0125] Exemplary plasma powers for inductively coupled plasma sources (e.g., transformer coupled plasma (TCP) sources available from Lam Research of Fremont, California) are 10 W to 1200 W, 20 W to 500 W, or 50 W to 300 W. Exemplary plasma powers for deposition operations range from 20 W to 200 W. Exemplary plasma powers for treatment operations range from 20 W to 1200 W.

[0126] Exemplary bias voltages range from 0V to -500V, 0 to -80V, such as -50V. The bias voltage may also be expressed in magnitude, such as 0 to 500V, 0 to 80V, or 0 to 50V. Exemplary flow rates for the deposition step are 1 sccm to 2000 sccm, 1 to 300 sccm, or 100 sccm. Exemplary flow rates for the treatment step range from 1 to 2000 sccm, 1 to 500 sccm, or 300 sccm. Exemplary substrate temperatures range from 40°C to 250°C or 60°C to 120°C. In some embodiments, the deposition and treatment exposure times may be 0.5s to 20s, or 3s to 10s, or 4s to 6s, with the treatment time of a multi-cycle process being taken as an example. In some examples, 10 to 100 cycles are performed.

[0127] experiment

[0128] The following examples are provided to further illustrate aspects of various embodiments. These examples are provided to illustrate and more clearly describe some aspects, but are not limiting.

[0129] An inductively coupled etch reactor is used to deposit a-Si build material on a hard mask for continuous and cyclic deposition with and without treatment. The deposition process gas is SiCl4 / H2, and H2-based plasma is used as a process step. The pressure varies between 20mTorr and 120mTorr.

[0130] For continuous PECVD, build material was deposited at 40mT for 60 seconds (s) and 120 seconds (s), while at 60mT for 75s. Pinch-off of the mask build material was observed at 120s / 40mT and 75s / 40mT. The deposition was non-conformal. For cyclic PECVD without treatment, build material was deposited at 40mT for 20 cycles of 3s (60s) and 40 cycles of 3s (120s) and 60mT for 25 cycles of 3s (75s). Pinch-off was observed for the 60mT case. The deposition was non-conformal. Comparison of the 120s / 40mT results (no pinch-off) with the 120s / 40mT results for continuous CVD shows that cycling contributes to well-defined high aspect ratio features. For cyclic PECVD with plasma treatment, build materials were deposited with 20 cycles of 3s deposition + 5s treatment and 40 cycles of 3s deposition + 5s treatment at 40 mT and 25 cycles of 3s deposition + 5s treatment at 60 mT. The deposition was non-conformal. No pinch-off was observed, indicating that the treatment is conducive to the deposition of high aspect ratio features over a wide pressure range.

[0131] The a-Si building material was deposited on the SiO2 hard mask using multiple deposition-treatment cycles using an inductively coupled etch reactor. The deposition process gas was SiCl4 / H2, the plasma power was 50W, and the pressure was 60mT. The treatment process gas was H2 with a small amount (about 5 volume %) of N2, the plasma power was 300W, and there was no bias on the substrate. 25 deposition-treatment cycles were performed. The bias voltage was changed for deposition, and the results are as follows:

[0132]

[0133]

[0134] An inductively coupled etch reactor was used to deposit a-Si build material on the hard mask using multiple deposition / treatment cycles. The SiCl4 / H2 flow rate was varied. For longer residence times (lower flow rates), pinch-off was observed. Without being bound by a particular theory, it is believed that longer SiCl x Species residence time leads to pinch-off. H radicals scavenge Cl reactions in the plasma. H radicals and ions eliminate overhang and pinch-off, providing efficient top mask etching and vertical sidewall profiles.

[0135] An inductively coupled etch reactor is used to deposit a-Si build material onto the hard mask using multiple deposition / treatment cycles. The plasma power during the deposition step is varied. Higher non-conformality is achieved with higher power. Without being bound by a particular theory, it is believed that SiCl with a high adhesion coefficient xThe concentration of free radicals and the concentration of H radicals that prevent overhang and pinch-off increase.

[0136] An inductively coupled etch reactor was used to deposit a-Si build material on a hard mask using multiple deposition / treatment cycles. The gas composition during the treatment step was varied. Using 100% H2 resulted in a necked profile. Without being bound by a particular theory, it is believed that the H2 plasma makes the already deposited a-Si film less reactive, thereby reducing the adhesion coefficient. The deposited film was etched and redeposited from the bottom of the trench to the top. A more vertical profile was observed by adding an additive gas (5 vol% N2 or 5 vol% CH4). Thicker deposition at the bottom of the trench was observed.

[0137] An inductively coupled etch reactor was used to deposit a-Si build material on a hard mask using multiple deposition / treatment cycles. The plasma power during the treatment steps was varied. The process gas was 100% H2. Powers of 0 W, 50 W, 100 W, 200 W, and 300 W were used. 300 W resulted in a necking profile. Reducing the power resulted in more vertical sidewalls and thicker trench and sidewall deposition, while 0 W resulted in pinch-off.

[0138] An inductively coupled etch reactor was used to deposit Si-containing build materials on the hard mask using multiple deposition / treatment cycles. The exposure time during the treatment step was varied. 1s, 2s, 3s and 5s were used. 5s resulted in a necked profile. Reducing the exposure time resulted in more vertical sidewalls and thicker trench and sidewall deposition.

[0139] in conclusion

[0140] Although the above embodiments have been described in some detail for the purpose of clear understanding, it is apparent that certain changes and modifications may be implemented within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems and devices of these embodiments. Therefore, the present embodiments should be considered illustrative rather than restrictive, and the embodiments are not limited to the details given in the present invention.

Claims

1. An apparatus for directional deposition on a patterned structure, comprising: a processing chamber having a substrate support therein; a plasma generator integrated with or connected to the process chamber and configured to generate plasma from one or more process gases; A controller including machine-readable instructions for: In a process chamber, depositing a material on a patterned structure in a multi-cycle deposition process, wherein the patterned structure includes a raised feature having a feature top, a feature bottom, and a feature sidewall connecting the feature top and the feature bottom, and wherein in each cycle: i) non-conformally depositing a first material on the patterned structure by a plasma enhanced chemical vapor deposition (PECVD) process such that a ratio of a thickness of the first material on a top portion of a feature to a thickness of the first material on a bottom portion of a feature is greater than 1; and ii) after depositing the first material, exposing the first material to a plasma capable of etching the first material, Wherein a first material is deposited directly on a first layer to be etched, and multiple deposition cycles are performed without etching the first layer during or between cycles. 2 . The device of claim 1 , wherein the first material is a silicon-based material, a carbon-based material, a boron-based material, or a combination thereof. 3 . The device of claim 1 , wherein the first material comprises two or more of silicon, carbon, boron, phosphorus, arsenic, and sulfur.

4. The apparatus of claim 1, wherein (ii) comprises exposing the first material to a nitrogen-based plasma, an oxygen-based plasma, a hydrogen-based plasma, a hydrocarbon-based plasma, an argon-based plasma, a helium-based plasma, or a combination thereof.

5. The apparatus of claim 1, wherein (ii) comprises exposing the first material to a plasma generated from a hydrogen-containing compound.

6. The apparatus according to claim 5, wherein the hydrogen-containing compound is one of H2, CH4, NH3, C2H2 and N2H2.

7. The device according to claim 1, wherein: The first material is an amorphous silicon-containing film.

8. The device according to claim 1, wherein: The raised features include an organic hard mask.

9. The device according to claim 1, wherein: The raised features include an inorganic hard mask.

10. The apparatus of claim 1, wherein (i) comprises forming polymer chains during the PECVD process.

11. The device of claim 10, wherein the polymer chains comprise chlorinated polysilanes.

12. The apparatus of claim 1, wherein (i) comprises applying a bias voltage during plasma enhanced chemical vapor deposition.

13. The apparatus of claim 1, wherein (ii) comprises etching the first material from a bottom of the feature.

14. The apparatus of claim 13, wherein (ii) comprises redepositing the etched material on top of the feature.

15. The apparatus of claim 1, wherein depositing by the PECVD process comprises forming a silicon-containing material using a silicon-containing precursor selected from a silane, a halogenated silane, an organosilane, or an aminosilane.

16. The device of claim 1, wherein deposition by a PECVD process comprises introducing a carbon-containing precursor selected from methane (CH4), acetylene (C2H2), ethylene (C2H4), propylene (C3H6), butane (C4H10), cyclohexane (C6H12), benzene (C6H6) and toluene (C7H8) to form a carbon-containing material.

17. The apparatus of claim 1, wherein depositing by the PECVD process comprises forming a metal-containing material using a metal-containing precursor.

18. The device according to claim 1, wherein: The plasma in (ii) is generated by a gas containing hydrogen (H2).

19. The apparatus of claim 1, wherein (ii) comprises generating a plasma species and chemically etching the first material with the plasma species.

20. The apparatus of claim 1, wherein (ii) increases the ratio of the thickness of all material on top of the feature to the thickness of all material on the bottom of the feature.

21. The apparatus of claim 1, wherein depositing the first material by a plasma enhanced chemical vapor deposition (PECVD) process comprises generating a plasma from a mixture of a silicon-containing precursor and hydrogen (H2) gas.

22. The device according to claim 1, wherein: The plasma generator is an inductively coupled plasma chamber.

23. The device according to claim 1, wherein The plasma generator is a capacitively coupled plasma generator.

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