Hydrogen gettering at buried defect layers in ion-implanted silicon by plasma hydrogenation and annealing

摘要

In this study gettering of atomic hydrogen in-diffused from a plasma hydrogenated surface into self ion implanted and annealed Si is investigated. Cz Si p-type samples were implanted with 3.5 MeV Si~+ ions to a fluence 5 x 10~(15) cm~(-2) and then annealed at 900 ℃. The hydrogenation of the samples was performed by exposure to the direct RF hydrogen plasma in a plasma enhanced chemical vapour deposition (PECVD) reactor. A remote deuterium plasma treatment was used as well. Secondary ion mass spectrometry (SIMS) was employed for analysis of the hydrogen/deuterium distributions. It is demonstrated for the first time that accumulation of diffused hydrogen occurs both at the projected range of the silicon ions, R_p, and at R_p/2. It is shown that hydrogen accumulation by vacancy-type defects at R_p/2 is as efficient as for trapping by dislocations at R_p.