High-performance long-wavelength HgCdTe infrared detectors grownon silicon substrates

Abstract

Long-wavelength HgCdTe heterostructures on silicon (100) substrates have been grown using metal-organic vapor phase epitaxy. Test diodes have been fabricated from this material using mesa technology and flip-chip bonding. We have demonstrated excellent resistance-area product characteristics for diodes with a 10.2μm cutoff wavelength. R0A values approaching 103Ωcm2 at 80K have been measured and the resistance-area product maintained above 102Ωcm2 at 1V reverse bias. Variable temperature R0A values correspond to expected generation-recombination loss mechanisms between 60 and 120K. Current-voltage characteristics of two diodes at opposite sides of an array indicate that a very uniform imaging long-wavelength infrared array could be fabricated from this material.

As Doping in (Hg,Cd)Te: An Alternative Point of View

“…H884 was grown in a 1'' reactor on the precursor assessment kit 33,34 while M274 was grown on a 4¢¢ MOVPE reactor 30 using (Me 2 N) 3 As as the arsenic precursor. The combined anneal is that used on material for device fabrication 30 and was carried out in a dedicated 4¢¢ MOVPE reactor at atmospheric pressure and consists of high-temperature ($410°C under an inert gas) and subsequent mercury vacancy-filling anneals. All other postgrowth heating and annealing experiments were carried out on the precursor assessment kit; 160°C and 370°C are the Hg heater and susceptor temperatures used for growth on this machine.…”

“…Two MCT layers, grown by MOVPE onto CdTeterminated II-VI MBE buffer layers on silicon (Si) as described previously, 30 were investigated. These were H884 (undoped, x $ 0.24, 6.5 lm thick) and M274 (SIMS As concentration 1.8 · 10 17 atoms cm -3 , x $ 0.24, 14.9 lm thick).…”

“…(Me 2 N) 3 As is now the As doping precursor of choice. 28,30 It can be seen from the above that, if the As is inactive as grown, then low-temperature (200°C to 250°C) Hg-rich mercury vacancy anneals are insufficient to activate it. A Hg-rich high-temperature (400°C to 500°C) anneal followed by a vacancyfilling anneal are required and even that may not be sufficient.…”

Influence of the Silicon Substrate on Defect Formation in MCT Grown on II-VI Buffered Si Using a Combined Molecular Beam Epitaxy/Metal Organic Vapor Phase Epitaxy Technique

“…QinetiQ has successfully demonstrated the fabrication of a number of different IR devices, including LW 10,11 and MW arrays and multiband 12 and negative luminescence device arrays 13,14 using the MBE/MOVPE combination. The devices have had excellent properties.…”

Environmental considerations in the MOVPE growth of (Hg,Cd)Te

“…In recent years, significant progress has been made in the use of metal organic vapour-phase epitaxy (MOVPE) for the growth of mercury cadmium telluride (MCT) for use in infrared devices and thermal imaging arrays [1]. The precursors used in the MOVPE growth include dimethylcadmium (Me 2 Cd) and di-iso-propyltelluride (Pr i 2 Te), which are at best noxious and at worst exceedingly toxic (MEL and LTEL are 0.025 and 0.1 mg m À3 , respectively) [2].…”