Abstract
The aim of this dissertation was to determine to which extent the
variation of the preparation parameters affected the optical properties
and homogeneity of a-Si :H films which were prepared from SiH 4 in a
capacitatively coupled rf glow discharge system. The following preparation
parameters were varied:
(i) pressure, (ii) power, (iii) rate of gas flow, (iv) with,
or without a mask, and (v) substrate temperature.
The influence of film thickness and aging became apparent during the
course of the project.
Conclusions drawn in this dissertation are based on processed data
obtained from approximately 450 transmission spectra from 95 a-Si:H films.
These spectra were obtained by means of a spectrophotometer.
Film thickness, variation in thickness 6d and optical properties such
as refractive index n, optical absorption and optical gap were obtained
from the abovementioned transmission spectra. Curve fitting was an
indispensable aid in the interpretation of results. 11 nd 11 images were
utilised and proved to be a non-destructive and simple technique to
monitor homogeneity and aging. Densities were determined by means of
a flotation method during which ZnC1 2 and ZnBr 2 solutions were utilised
as flotation mediums.
The section of research which refers to (i) - (iv), shows that a complex
and interdependent relation exists between optical properties and the
preparation parameters (pressure, power and rate of gas flow).
Noteworthy results are as follows:..
M.Sc.