Photo Luminescence from Si Films fabricated by Double Tubed Coaxial Line Type Microwave Plasma CVD Apparatus
Abstract
In this study, we used a double tubed coaxial line type microwave plasma CVD apparatus. Under the low gas pressure ( ~mtorr), a-Si:H film is fabricated and photo luminescence (PL) is not observed at room temperature. However, under the high gas pressure ( ~100mtorr), a-Si:H nanoball film is fabricated and PL is observed at room temperture. The diameter of a-Si:H nanoball is about 20nm. It is judged by X-ray diffractmeter that there are nanocrystal Si (nc-Si) in this a-Si:H nanoball. The diameter of nc-Si is about several nm. In this work, we fabricated the a-Si:H nanoball films varying the substrate DC bias voltage from -80V to +40V, the substrate temperture during deposition from R.T. to 400^oC and the gas flow rate of SiH4 per total gas flow (which consists of SiH4 and Ar) from 7% to 36%. When the films are oxidized at 80^oC for more than the several hours, the PL ( ~800nm) is observed at R.T.. We discuss how the deposition circumstances affect the property and the film characteristics. The result will be presented at the meeting.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 1998
- Bibcode:
- 1998APS..GECEMP417K