S. J. Noh*, H. S. Kim, C. Y. Kim, H. S. Bhang** and H. K. Jang**

Dept. of Applied Physics, Dankook Univ., Seoul 140-714, Korea
jnoh@ns.dankook.ac.kr
**Dept. of Physics, Korea Univ., Seoul 136-701, Korea

Polycrystalline-silicon p-channel metal-oxide-semiconductor thin film transistors (poly-Si PMOS TFTs) are used for the load devices of high-density static random access memories (SRAMs). In this paper, the effects of plasma hydrogenation on a SiO2/Poly-Si interface and Poly-Si grain boundaries are presented. For the gate oxides, high temperature SiO2 dielectric films of 500 - 1000 thickness were deposited on the (100) single crystalline silicon wafers in a low-pressure chemical vapor deposition (LPCVD) reactor. For the poly-Si active layers, poly-Si films of 500 - 1500 thickness were deposited in an LPCVD reactor and doped by BF2 ion implantation from 30 keV to 80 keV. After this, various treatments by hydrogen plasmas were performed to induce the trap density changes at the SiO2/poly-Si interface and the Poly-Si grain boundaries. The behaviors of the electrically activated defects have been investigated before and after the plasma hydrogenation process. For the defect analysis, electron spin resonance (ESR) measurements were performed from low temperature ( 20 K) to room temperature and the electrical measurements using a capacitance - voltage method and a time dependent dielectric breakdown (TDDB) method were also carried out.