Development of TlGaAs/GaAs materials for High Speed Electronic Devices

High-performance, low cost monolithic radio-frequency integrated circuits (RFIC) have many applications for ARMY, other DOD components, and commercial site. The need for RFIC operating in the high mm-wave range stresses the current GaAs based PHEMTtechnology to its limits, and has spurred development effort of InP based HEMT/PHEMT. The cost of InP based HEMT/PHEMT is very high due to expensive, much smaller and less robust substrate, and the InP-specific fabrication steps. Calculations predict thatTlGaAs based PHEMT on GaAs has better device performance figures over current GaAs based PHEMT and is comparable to InP based HEMT. When considering the mature GaAs MESFET and PHEMT technology with 4 inch and 6 inch fab lines, retaining GaAs substrate inmanufacturing operation, as opposed to switching to InP substrates, is highly desirable. ELI proposes to develop a TlGaAs based PHEMT on GaAs substrate. TlGaAs on GaAs PHEMT will offer many advantages over present technologies. These include improvedperformance with reduced cost, better reliability, and lower leakage currents. In phase I, TlGaAs/GaAs 2DEG growth and characterizations will be carried out, and high performance PHEMT device will be realized in phase II.TlGaAs based high speed, low costPHEMT has many applications in both military and commercial sectors. These applications include but are not limited to hand-held personnel communication systems, automotive collision warning radars, digital radios, satellite communication system,phased-array radar, and wireless local area network(WLAN)