Advanced LWIR HgCdTe detectors for strategic applications
- Rockwell Science Center, Thousand Oaks, CA (United States)
- Aerojet Electronic Systems Division, Azusa, CA (United States)
The demand for high detectivity LWIR IR focal plane arrays that operate at low backgrounds is shown to drive the HgCdTe technology toward increased detector performance. Reduced operating temperature together with advanced material technology and detector design are presented as solutions. High performance MWIR, MLWIR and LWIR HgCdTe detector test arrays and variable area test structures were recently demonstrated through the joint collaboration of Aerojet Electronic Systems Division and Rockwell International. These devices are based on the innovative buried planar heterostructure (BPH) detector architecture grown by liquid phase epitaxy of HgCdTe on II--VI substrates. The major features of the BPH design include planar geometry, heterostructure wide gap p-type on narrow gap n-type HgCdTe and a buried LWIR electrical junction. Excellent 78K median R{sub o}A performance across the IR spectrum from 5.2 {micro}m to 12 {micro}m is reported and shown to follow the diffusion trend line. Excellent 40K median R{sub o}A performance for devices with cutoffs ranging from 9 {micro}m to 19 {micro}m are also presented. LWIR R{sub o}A statistical performance data at both 78K and 40K from fanout test arrays are presented with median R{sub o}A values of 100 ohm-cm{sup 2} at 78K and > 10{sup 6} ohm-cm{sup 2} at 40K for cutoffs of 10.4 {micro}m and 11.4 {micro}m respectively. The 90% test array operability was found to exceed 5 {times} 10{sup 5} ohm-cm{sup 2} at 40K. Devices with median R{sub o}As of 20 ohm-cm{sup 2} at 78K and 7 {times} 10{sup 5} ohm-cm{sup 2} at 40K were measured for cutoffs of 12 {micro}m and 13 {micro}m respectively. Uniform and high quantum efficiencies were measured at 40K with a median of {approximately} 70%.
- OSTI ID:
- 207948
- Report Number(s):
- CONF-940449--; ISBN 0-8194-1521-9
- Country of Publication:
- United States
- Language:
- English
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