Enhancement of Crystal Growth in Si Thin-Film Deposition by H-Radical-Assisted Magnetron Sputtering

We developed a new Si sputtering deposition system with an additional H-radical source, called H-radical-assisted magnetron sputtering (HRAMS). This system enables us to prepare a microcrystalline film even at a low total gas pressure of 3 mTorr and the crystalline volume fraction increased steeply from 41 to 77% with increasing total gas pressure from 3 to 5 mTorr, although a conventional H(2)/Ar mixture sputtering system prepared an amorphous film at total gas pressures of 5 mTorr and below. In addition, the crystallinity of the films prepared by HRAMS was higher than that by the conventional magnetron sputtering at a H(2) partial pressure ratio lower than 10%. These improvements of crystallinity by HRAMS may be attributed to both or one of the following two effects. One is the supply of H atoms produced in the radical source to the film-growing surface, resulting in the enhancement of H coverage on the film-growing surface. The other effect is the enhancement of the generation of SiH(x) species as deposition precursors by the reactive ion etching (RIE) effect on the Si target surface. (C) 2010 The Japan Society of Applied Physics