研究紹介
低速陽電子による SiO2 膜の評価
上殿 明良，谷川 庄一郎
応用物理, 第64巻,
第1号, pp.43-46 (1995)
エネルギー可変の陽電子を用いて，熱酸化やCVD法により，Si基板上に形成したSiO2膜の評価を行った．SiO2膜中に打ち込まれた陽電子は，ポジトロニウム(Ps)という電子と陽電子の水素様束縛状態から消滅する．このPsの振る舞いを調べることによって，SiO2膜の空隙や不純物などについての情報を得ることができることがわかった．本稿では，陽電子消滅による物性研究の解説を含めて，陽電子消滅によって，SiO2膜を評価した結果について紹介する．
Akira UEDONO and Shoichiro TANIGAWA
OYO BUTURI,
vol.64,
No.1, pp.43-46 (1995)
Slow positrons were used as a probe for defect detection in SiO2 films grown on Si substrates. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured as a function of incident positron energy for SiO2/Si specimens fabricated by thermal oxidation or by chemical vapor deposition. Positrons implanted into SiO2 films were found to annihilate from positronium (Ps) states. From measurements of the formation probability of Ps and its lifetime, information about open-volume defects and impurities such as hydroxyl groups in SiO2 films was derived. The present investigation shows the potential of slow positrons as a nondestructive probe thin SiO2 films.
Keywords : SiO2, thermal oxidation, CVD, detect, slow positron, doppler broadening profile, lifetime