[20a-A406-1~9] 13.4 Si系プロセス・Si系薄膜・MEMS・装置技術

▲ [20a-A406-2] Dissociation Reaction of Si₂Cl₆ on Si(100): the Scanning Tunneling Spectroscopy Study

〇Leonid Bolotov¹、Hidetoshi Mimura²、Yunosuke Sakai²、Tetsuo Yamamoto²、Takafumi Sasaki²、Noriyuki Uchida¹ (1.AIST-DTech、2.Kokusai Elec. Co.)

キーワード：silicon precursor, surface analysis, scanning tunneling spectroscopy

Gas reaction processes have become useful methods for controllable growth of ultrathin silicon nitride films in CMOS and memory technologies. Hexachlorodisilane (HCDS, Si₂Cl₆) is a promising precursor due to thermal stability, low reaction barrier and high Si content, allowing fast growth at low temperature. Here, employing a ultimate sensitivity of scanning tunneling spectroscopy (STS) to details of the surface electronic structure, we are able to assess distributions of reaction products on Si(100) surfaces as a function of HCDS exposure dose at a nanometer scale.
For statistical analysis, arrays of position-dependent STS spectra were recorded along the reacted Si(100) surfaces in the spectroscopy mode. We recognized four classes of STS spectra as fingerprints of HCDS dissociation products on the Si(100) surface. STS maps and statistical data show that significant fraction of the exposed Si surface remains accessible in HCDS gas reaction process at the exposure conditions.