Rapid thermal annealing of LPCVD-SOI substrates for sensor applications
✍ Scribed by P. Jeanjean; P. Sellitto; J. Sicart; J.L. Robert; M. Le Berre; G. Chaussemy; P. Pinard
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 275 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0924-4247
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✦ Synopsis
Rapid thermal anneals (RTA) have been performed on boron and arsenic-implanted LPCVD polysilicon films. We have investigated the electrical properties of highly implanted films (4 x 1014, 8 x lOI and 5 x 10" cm-') using Hall techniques. The experimental results are compared with those obtained on conventionally annealed (CTA) films. The electrical dopant efficiency and Hall mobility are measured at room temperature in the two series. We find that they are higher in RTA films. Thus the RTA-processed polysilicon substrates have the lowest resistivity. This result is of the highest importance in using implanted LPCVD amorphous-or polycrystalline silicon layers for low-cost, thin, film sensors. The density, N,, of trapping centers at grain boundaries (GB) is derived from electrical data (i.e., from the Hall carrier concentration and the GB potential barrier height, E,). We find that it does not depend significantly on the implant species and heat-treatment.
In contrast, it depends strongly on the implantation dose. The temperature coefficient of the resistivity is found to be positive or negative depending on the implantation dose. This striking result is clearly interpreted in terms of GB barrier potential scattering.