D-band (110–170 GHz) InP gunn devices

• Published in: Solid-state electronics 1993-11, Vol.36 (11), p.1547-1555
• Main Authors: Kamoua, R., Eisele, H., Haddad, G.I.
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Microwave and submillimeter wave devices, electron transfer devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0038-1101; 1879-2405
• DOI: 10.1016/0038-1101(93)90026-M

This paper reports on the development of InP Gunn sources for operation in the D-band (110–170 GHz). n +− n− n + structures with flat doping as well as graded doping profiles have been considered. Oscillations were obtained at 108.3 GHz from a 1 μm structure with a uniform n doping of 2.5 × 10 16 cm −3. The CW RF output power was 33 mW. A 1 μm graded structure with an n doping increasing linearly from 7.5 × 10 15 to 2.0 × 10 16 cm −3 has resulted in 20 mW at 120 GHz and 10 mW at 136 GHz. These results are believed to correspond to a fundamental mode operation and represent the state-of-the-art performance from InP Gunn devices at these frequencies. This improvement in performance is attributed in part to a processing technique based on the use of etch-stop layers and InGaAs cap layers. An etch-stop layer allows low-profile mesas (2–3 μm) and InGaAs cap layers help reduce the contact resistance, thus minimizing series resistances in the device. In addition, a physical model based on the Monte Carlo method was developed to aid in the design of structures for high frequency operation. Experimental results obtained from a 1.7 μm Gunn device operating at W-band frequencies were used to estimate appropriate InP material parameters.