Ha. Naseem et al., HIGH-PRESSURE HIGH-POWER MICROWAVE PLASMA CHEMICAL-VAPOR-DEPOSITION OF LARGE-AREA DIAMOND FILMS, Thin solid films, 308, 1997, pp. 141-146
Uniform, large area, smooth, and chemically clean diamond films having
low residual stress are important for many applications such as elect
ronic packaging, metallurgical and optical coatings, and X-ray lithogr
aphy masks. Uniform diamond films were deposited on 75 mm diameter p-t
ype (100) silicon substrates using a Wavemat Inc. microwave plasma dis
c reactor (MPDR) which was modified for high pressure and high power o
perations. These high pressure high power deposited films yielded much
better quality even though the deposition rate increased by more than
50% when compared to films deposited under low pressures and powers.
A dry abrasive seeding technique was used that was simple but offered
very high nucleation density. The CH4 concentration was varied over 0.
5-3.0% and the deposition pressure and power were set at 67 Torr and 3
500 W, respectively. Deposited films were characterized by SEM, AFM, R
aman, and X-ray diffraction (XRD) techniques. For increasing CH4 flow
from 0.5 to 3%, the deposition rate increased by four times without mu
ch reduction in the film quality, as observed by Raman spectroscopy. F
or CH4 flow rate of up to 2%, the film texture was (111) whereas it ch
anged to [220] for films deposited at 3% CH4. The macro-and micro-stre
ss in the films were measured by XRD d-sin(2) psi technique and diffra
ction peak broadening, respectively. All the deposited films showed mo
derate compressive macro-stress; the micro-stress values for these sam
ples were much less than observed for films deposited in low-pressure
low power regime. (C) 1997 Elsevier Science S.A.