Scale-up of LPE processes for flexibility in manufacturing

Focal plane arrays fabricated in Hg 1-x Cd x Te have matured to the point where they are entering pilot production for military and civilian applications. Loral chose the p-on-n heterostructure photodiode architecture produced by a two step LPE process for production scale-up because of its demonstrated high performance over a broad range of cut-off wavelengths from approximately equals 4 micrometers to > 15 micrometers . To meet the manufacturing requirements of high throughput and flexibility, Loral has successfully scaled and transferred into production, both tellurium rich horizontal slider (for growth of the active n-type base layer) and mercury rich vertical dipping (for growth of the p-type cap layer) technologies. This approach capitalizes on the advantages of each process to maximize the producibility of LPE films in a manufacturing environment. This paper discusses the advantages of horizontal Te-rich growth. Production reactors have demonstrated excellent compositional uniformity (+/- 0.005 in x) over 24 cm 2 . Issues related to the scale-up of the equipment are discussed.