The degradation associated with prolonged operation of GaAs diodes under large forward bias has been investigated. It is observed that the degradation rate increases with temperature and that the fractional percent degradation per unit time interval increases as exp (−E0/KT) for most devices. The value of E0 is about 0.45 ± 0.1 eV. It is shown that contamination of devices with copper increases the degradation rate. The 1.28-eV emission band in the degraded Cu-contaminated devices is enhanced relative to the band-edge emission at low temperatures. A Cu-contamination model for the degradation is considered which shows agreement with experimental data. Accordingly, the degradation is attributed to the diffusion of interstitial copper ions in the p region of the devices toward the junction during operation at high-current densities.
A monolithic 128 x 128 InSb array is described for staring infrared imaging systems operating in the 3 -5pm spectral region. The array is fabricated with only 4 mask levels and has almost 5 times higher responsivity and nearly 14 times greater wafer yield as compared to a previous design. The higher responsivity has resulted in demonstration of significantly improved thermal imagery.
This paper describes a novel bipolar technology, the Schottky-Base I L, which offers significant advantages in terms of packing density, device performance, and reduced LS circuit complexity as compared to conventional I L designs. A pnp transistor fabricated in an n-epitaxial layer on a ptsubstrate forms the active switch for this design. Current source to the pnp is provided by an npn transistor. Schottky diodes are formed on the pnp base which is merged with the npn(injector) collector. Hence, the basic logic gate in this des i g n i s a multi-input, multi-output NAND gate. B e c a u s e a n n -o n -p t y p e s t r u c t u r e i s u s e d , T T L , STTL, or ECL circuits can be made readily available on chip. Design trade-offs for optimizing the speed-power performance are described. Experimental data on a test chip indicate pnp c u rrent gain of -80 and a minimum delay of 10 n s of the SB12L gate using 7.5 pm minimum linewidths. 2 z
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.