| Popis: |
Nanocrystal Si (nc-Si) sensitization of Er in a silica matrix to obtain high optical activity in a Si-compatible material is investigated. Er-doped silicon-rich silicon oxide (SRSO) films, which consist of nc-Si embedded inside an SiO2 matrix, were deposited by electron-cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) using SiH4 and O2 with concurrent sputtering of Er followed by a high temperature anneal. For comparison, Er-free SRSO films were also deposited. Detailed investigation of processing conditions indicates that an annealing process consisting of 30 min anneal at 950°C without hydrogenation to be optimum for activation of Er. Investigation of MOS diode structure with Er-doped and Er-free SRSO films indicates that a mesa-type structure with n+ poly-silicon top contact, p-type substrate, and SRSO Si content of less than 40% gives the best diode performance. Er-free SRSO diodes fabricated using the optimum conditions show electroluminescence under forward bias. Er-doped SRSO diodes show photoresponse at 1.54 μm due to nanocrystal -- Er interactions, showing the promise of developing integrated, Si-based 1.54 μm light detectors for integrated microphotonic devices. |
