PRECURSOR FOR THIN Si-CONTAINING FILM DEPOSITION
Publication Date: 2017-Jun-21
The IP.com Prior Art Database
The authors found that cyclic hexasilane molecules with the general formula Si6X12 wherein X is independently H, an alkyl or a halide have suitable properties for deposition of Si-containing film on various substrates or mixed substrates for semiconductor or photovoltaic applications. The preferred Si-containing films are a-Si, c-Si and SiO2. In the present invention, the authors found that using a cylic compound with the general formula Si6X12 with a cyclic pentasilane compound of general formula Si5X10 wherein for each compound X is independently selected from H, alkyl or halide. In one preferred embodiment, the alkyls are selected from but without limitation Me, Et, Pr, iPr, nPr, Bu, tBu, iBu; the halides are selected from Cl, F, I. In one particular case, the authors found that adding silane, preferably at around 10%, can be used to enhance the deposition process.
In one preferred embodiment of the invention, the authors found that the cyclic substituted hexasilane is preferably selected from but with out limitation Si6Cl12, (SiHMe)6, (SiHEt)6, (SiMe2)6, (SiMeEt)6, (SiHPr)6, (SiHiPr)6, (SiHnPr)6, (SiHBu)6, (SiHtBu)6 or (SiHiBu)6. The cyclic pentasilane is preferably selected from but without limitation Si5Cl9(SiCl3), (SiHMe)5, (SiHEt)5, (SiMe2)5, (SiMeEt)5, (SiHPr)5, (SiHiPr)5, (SiHnPr)5, (SiHBu)5, (SiHtBu)5 or (SiHiBu)5.
The authors also found that using cylic compound with the general formula Si6X12 with a cyclic pentasilane compound of general formula Si5X10 wherein for each compound X is independently selected from H, alkyl or halide can be used for SiO2 deposition, for instance for gap filling applications. In gap fill applications, it is important to have a “flow-like” deposition (the deposition is faster at the bottom of the structure and the hole is progressively filled) to avoid void formation and to be able to completely fill the structure. SiO2 deposition can be done by combining the cyclic hexasilane compound with the cyclic pentasilane with or without addition of silane to enhance the deposition process (the preferred silane content would be around 10%), with oxidizers such as H2O, O2, O3, H2O2, carboxylic acid or a combination thereof. The deposition method is preferably Chemical Vapor Deposition with or without a plasma source (direct plasma or remote plasma for instance) but the authors also consider alternative deposition techniques such as ALD, Cat-CVD, pulsed CVD or any state-of-the-art combination techniques (using a plasma source or not).
In the present invention, the authors found that cyclohexasilane (CHS) and methycylopentasilane (MCPS) can be used for a-Si or poly-Si film deposition on various substrates of mixed substrates. The Si-containing film can be used for semiconductors or photovoltaic applications. In another embodiment, the authors found that mixing CHS and MCPS with silane can improve the deposition properties. Preferably, 10%...