Diamond and Related Materials 11 (2002) 433–436 0925-9635/02/$ - see front matter  2002 Elsevier Science B.V. All rights reserved. PII: S0925-9635 Ž 02 . 00010-9 Imaging deep UV light with diamond-based systems Stuart P. Lansley , Olivier Gaudin , Haitao Ye , Nadeem Rizvi , Michael D. Whitfield , a a a b b Robert D. McKeag , Richard B. Jackman * c a, Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, UK a Exitech Limited, Hanborough Park, Long Hanborough, Oxford OX8 8LH, UK b Centronic Ltd., Centronic House, King Henry’s Drive, New Addington, Croydon CR9 OBG, UK c Abstract Diamond grown by chemical vapour deposition (CVD) techniques has shown great promise for the fabrication of high sensitivity, low dark current, fast and visible-blind deep UV photodetectors. In addition to the careful choice of substrate material, defect passivation treatments applied to the diamond after growth have been found to considerably enhance the detector characteristics achieved. In this paper, we report on the first purposefully designed one-dimensional CVD diamond imaging array for the detection of nanosecond 193-nm excimer laser pulses using this approach. It is shown to perform extremely well, giving less than 2% pixel-to-pixel variation in signal response, and is fast enough to avoid any sign of charge build-up during prolonged operation.  2002 Elsevier Science B.V. All rights reserved. Keywords: Photodetectors; UV imaging; Photoconductivity 1. Introduction The case for the use of diamond-based structures for the detection of deep UV light has been well made over the last few years w1–26x. The wide band-gap (5.5 eV, 225 nm) and high resistivity of ideal diamond suggests that relatively simple photoconductive devices should operate as ‘visible-blind’, low dark current deep UV sensors. It is also well known that photoconductive devices can display gain, offering the prospect of high levels of sensitivity w27x. Despite this promise, many examples of chemically vapour-deposited (CVD) dia- mond-based detectors have failed to perform with com- mercially useful characteristics, with poor wavelength selectivity and prolonged turn-off times (charging) being the most common problems encountered. We have pre- viously shown that careful device design along with the application of post-growth diamond defect passivation treatments can alleviate these problems and we have produced high performance detectors that are now pro- duced commercially w3,23,25,26x. These point-source devices have found many uses in the detection of deep *Corresponding author. Tel.: q44-207-679-1381; fax: q44-207- 388-9325. E-mail address: r.jackman@ee.ucl.ac.uk (R.B. Jackman). UV light within materials processing and environmental monitoring applications. A number of reviews of the characteristics and applications for these devices exist w28,29x. However, there is also a considerable need to image deep UV light and it is the realisation of the first such diamond-based device that is the subject of this paper. One-dimensional imaging arrays have been pro- duced which are fast, ‘visible-blind’, sensitive, and which display little pixel-to-pixel variation in sensitivity. The devices have been evaluated in terms of their usefulness for profiling ArF (193 nm) excimer laser beams within photolithography processes within the semiconductor industry. 2. Experimental methods All experiments were carried out on 10 mm laser cut 2 samples of free-standing polycrystalline diamond, grown by microwave plasma-enhanced CVD. The films were of high quality, approximately 100 mm thick with random morphology and a typical grain size of 20–40 mm; further details have been given elsewhere w7x. Prior to the formation of electrical contacts, the diamond was subjected to a standard acid treatment designed to remove contamination, residual sp and any conductive 2 hydrogen layer on the surface w30x. Interdigital gold