Md. Whitfield et al., High-speed diamond photoconductors: a solution for high rep-rate deep-UV laser applications, DIAM RELAT, 10(3-7), 2001, pp. 650-656
Beam monitoring of excimer lasers operating at high powers in the deep ultr
a-violet (DUV) is becoming increasingly important, due to the rapid prolife
ration of these systems in micromachining, photolithography, and other area
s of industrial interest. This task requires radiation-hard detectors able
to operate effectively for extended periods at high laser rep-rates. DUV-vi
sible-blind photoconductors can be fabricated on polycrystalline CVD diamon
d, a material that is intrinsically radiation-hard and visible-blind. Howev
er, the performance of detectors fabricated on as-grown material is insuffi
cient to meet the requirements of many excimer laser applications. In this
paper, we show that sequentially applied post-growth treatments can progres
sively change both the gain and speed of these devices. Charge-sensitive de
ep-level transient spectroscopy (Q-DLTS) and transient photoconductivity (T
PC) has been used to study the effect of these treatments on the defect str
ucture of our thin-film diamond detector material, For the first time, we r
eport the successful operation of a diamond photoconductive device with lin
ear bias and fluence-response characteristics at more than 1 kHz at 193 nm.
(C) 2001 Elsevier Science B.V. All rights reserved.