Directional deposition on patterned structures

Abstract

Provided herein are methods and related apparatus that facilitate patterning by performing highly non-conformal (directional) deposition on patterned structures. The methods involve depositing films on a patterned structure, such as a hard mask. The deposition may be both substrate-selective such that the films have high etch selectivity with respect to an underlying material to be etched and pattern-selective such that the films are directionally deposited to replicate the pattern of the patterned structure. In some embodiments, the deposition is performed in the same chamber as a subsequent etch is performed. In some embodiments, the deposition may be performed in a separate chamber (e.g., a PECVD deposition chamber) that is connected to the etch chamber by a vacuum transfer chamber. The deposition may be performed prior to or at selected intermittences during at etch process. In some embodiments, the deposition involves multiple cycles of a deposition and treatment process.

1 . A method comprising:
 performing a multi-cycle deposition process to deposit a mask-built up material on a patterned structure, wherein the patterned structure comprises features having features tops, feature bottoms, and feature sidewalls connecting the feature tops and feature bottoms and each cycle comprises:
 i) depositing by a plasma enhanced chemical vapor deposition (PECVD) process a first material non-conformally on the patterned structure, wherein the thickness of the deposited first material on a feature top is greater than a thickness of the deposited first material on a feature bottom such that a ratio of the thickness of the first material on a feature top to the thickness of the first material on a feature bottom is greater than 1, and 
 ii) plasma treating the first material to increase the ratio of the thickness of the first material on a feature top to the thickness of the first material on a feature bottom. 
   
     
     
         2 . The method 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 method of  claim 1 , wherein the first material comprises two or more of silicon, carbon, boron, phosphorous, arsenic and sulfur. 
     
     
         4 . The method of  claim 1 , wherein the first material is a metal-containing material. 
     
     
         5 . The method of  claim 1 , wherein (ii) comprises exposing the first material to an 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. 
     
     
         6 . The method of  claim 1 , wherein (ii) comprises exposing the first material to a plasma generated from a hydrogen-containing compound. 
     
     
         7 . The method of  claim 5 , wherein the hydrogen-containing compound is one of H 2 , CH 4 , NH 3 , C 2 H 2 , and N 2 H 2 . 
     
     
         8 . The method of  claim 1 , further comprising etching a layer masked by the patterned structure. 
     
     
         9 . (canceled) 
     
     
         10 . The method of  claim 1 , wherein treating the first material comprises redepositing the first material from the feature sidewalls to the feature tops. 
     
     
         11 . The method of  claim 1 , wherein each cycle further comprises reacting the first material to form a second material. 
     
     
         12 . The method of  claim 1 , wherein each cycle further comprises changing a material property of the first material. 
     
     
         13 . The method of  claim 12 , wherein the changing the material property of the first material comprises one or more of a plasma treatment, exposure to ultraviolet radiation, or a thermal anneal. 
     
     
         14 . The method of  claim 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 to a plasma reactor. 
     
     
         15 . The method of  claim 14 , wherein depositing by the PECVD process comprises introducing a silicon-containing precursor selected from a silane, a halogenated silane, an organosilane, or an aminosilane. 
     
     
         16 . The method of  claim 14 , wherein depositing by the PECVD process comprises introducing a silicon-containing precursor selected from methylsilane, ethylsilane, isopropylsilane, t-butylsilane, dimethylsilane, diethylsilane, di-t-butylsilane, allylsilane, sec-butylsilane, thexylsilane, isoamylsilane, t-butyldisilane, di-t-butyldisilane, tetrachlorosilane, trichlorosilane, dichlorosilane, monochlorosilane, chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, t-butylchlorosilane, di-t-butylchlorosilane, chloroisopropylsilane, chloro-sec-butylsilane, t-butyldimethylchlorosilane, thexyldimethylchlorosilane, mono-aminosilane, di-aminosilane, tri-aminosilane, tetra-aminosilane, t-butylaminosilane, methylaminosilane, tert-butylsilanamine, bis(tertiarybutylamino)silane, or tert-butyl silylcarbamate. 
     
     
         17 . The method of  claim 14 , wherein depositing by the PECVD process comprises introducing a carbon-containing precursor selected from methane (CH 4 ), acetylene (C 2 H 2 ), ethylene (C 2 H 4 ), propylene (C 3 H 6 ), butane (C 4 H 10 ), cyclohexane (C 6 H 12 ), benzene (C 6 H 6 ), and toluene (C 7 H 8 ). 
     
     
         18 . The method of  claim 14 , wherein depositing by the PECVD process comprises introducing a boron-containing precursor selected from borane (BH 3 ), diborane (B 2 H 6 ), and triborane (B 3 H 7 ). 
     
     
         19 . The method of  claim 14 , wherein depositing by the PECVD process comprises introducing a metal-containing precursor selected from pentakis(dimethylamido)tantalum, trimethylaluminum, tetraethoxytitanium, tetrakis-dimethyl-amido titanium, hafnium tetrakis(ethylmethylamide), bis(cyclopentadienyl)manganese, and bis(n-propylcyclopentadienyl)magnesium. 
     
     
         20 . The method of  claim 1 , wherein or both of the PECVD process and the plasma treating operation use an inductively-coupled plasma, or a capacitively-coupled plasma, or a microwave plasma. 
     
     
         21 . The method of  claim 1 , wherein one or both of the PECVD process and the plasma treating operation uses a direct plasma, or a remote plasma, or a combination thereof. 
     
     
         22 . The method of  claim 1 , wherein one or both of the PECVD process and the plasma treating operation is ion-assisted process, or radical-assisted process, or a combination thereof.