InAs Device Process Development and Characterization

Abstract

Standard Form 298 (Rev. 8-98)Prescribed by ANSI Std. Z39.18Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) SPONSOR / MONITOR'S ACRONYM(S) 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR / MONITOR'S REPORT NUMBER(S) 202-404-4623This report summarizes the results of the initial effort in InAs bipolar device development. InAs is one of the III-V semiconductor materials exhibiting a relatively small energy bandgap and extremely high electron mobility, properties both desirable for high-frequency, low-power dissipation device applications. The major accomplishment of this work is the development of a robust device fabrication process that can be directly transferred to an industrial environment. Ti/Pt/Au was used as a universal n-and p-type contact with record low contact resistances. For the base access etch, which is one of the critical issues for bipolar device processing, a unique doping dependence etch was discovered for InAs that allows the base access etch to stop at the appropriate layer. The low-bandgap InAs and heavy doping resulted in premature breakdown through current tunneling and uncontrollable reverse leakage current. This effect was addressed successfully through interactive MBE growth, device characterization, and material analysis techniques. Pn junctions, the building blocks for bipolar transistors were produced with reverse leakage current as low as 10 mA at -1 V and breakdown voltages as high as 6.5 V. The InAs pn junctions produced had promising rectifying diode characteristics for low-voltage operation and high-speed current amplifier applications.