[18p-E304-1~10] 13.4 Si processing /Si based thin film / MEMS / Equipment technology

[18p-E304-4] Chemical reaction of boron trichloride gas at silicon surface

〇Mitsuko Muroi¹, Ayami Yamada¹, Ayumi Saito¹, Hitoshi Habuka¹ (1.Yokohama Nat. Univ.)

Keywords:epitaxial growth, silicon, doping

In the process of forming a semiconductor Si thin film by chemical vapor deposition, it is necessary to add a dopant (doping) to adjust the resistivity, so that n-type and p-type doping gases are respectively phosphine (PH₃) and Diborane (B₂H₆) is used. B₂H₆, which is mainly used in p-type, is flammable and toxic, has a high risk, and is designated as a specific high pressure gas, so care must be taken in its handling. On the other hand, boron trichloride (BCl₃) is mentioned as a safe doping gas. BCl₃ is noncombustible, although it has a pungent odor, and is safer than B₂H₆. However, since BCl₃ is widely known as an etching gas, etching may be accompanied by doping. So, in this research, in order to use BCl₃ which is a safe gas for B doping of Si film, since the chemical reaction on the Si substrate surface was investigated, it reports in detail.