caa a22 4500 388019352 CHVBK 20180307124919.0 cr unu---uuuuu 161130e199810 xx s 000 0 eng 10.1557/JMR.1998.0387 doi S0884291400046227 pii (NATIONALLICENCE)cambridge-10.1557/JMR.1998.0387 Probing of microvoids in high-rate deposited a-Si: H thin films by variable energy positron annihilation spectroscopy [Elektronische Daten] In this paper, positron annihilation measurements have been carried out on a-Si: H thin films deposited by plasma-enhanced chemical vapor deposition (PECVD) at high and low rates by means of the variable energy positron beam Doppler-broadening technique. The depth profiles of microvoids in the films grown under different conditions have been determined. We found a smaller void fraction in the surface region of all films compared to the bulk, and a smaller void fraction in low rate than in high growth rate films. By plotting S and W parameters in the (S, W) plane, we have shown that the vacancies in all of the high-rate and low-rate deposited intrinsic samples, and in differently doped low-rate samples are of the same nature, although there appears to be a higher density of defects in the boron than phosphorus doped films. The depth profiles of the microvoid-like defects in the a-Si: H films are extracted by use of the vepfit program. Copyright © Materials Research Society 1998 Zou X. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Webb D. P. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Chan Y. C. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Lam Y. W. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Hu Y. F. Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong Fung S. Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong Beling C. D. Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong Journal of Materials Research Cambridge University Press 13/10(1998-10), 2833-2840 0884-2914 13:10<2833 1998 13 JMR https://doi.org/10.1557/JMR.1998.0387 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1557/JMR.1998.0387 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zou X. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong NATIONALLICENCE 700 1- Webb D. P. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong NATIONALLICENCE 700 1- Chan Y. C. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong NATIONALLICENCE 700 1- Lam Y. W. Department of Electronic Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong NATIONALLICENCE 700 1- Hu Y. F. Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong NATIONALLICENCE 700 1- Fung S. Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong NATIONALLICENCE 700 1- Beling C. D. Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong NATIONALLICENCE 773 0- Journal of Materials Research Cambridge University Press 13/10(1998-10), 2833-2840 0884-2914 13:10<2833 1998 13 JMR CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge