W. Behr

Bio: W. Behr is an academic researcher from Bell Labs. The author has contributed to research in topics: Diode & IMPATT diode. The author has an hindex of 2, co-authored 3 publications receiving 102 citations.

A 90-GHz double-drift IMPATT diode made with Si MBE

Abstract: For the first time silicon double-drift IMPATT structures have been grown completely by Si molecular-beam epitaxy. The n-type layers are grown at 750 °C on low-resistivity n+-type substrates followed by p-type layers at 650 °C. The highly doped p+-layers are grown by solid-phase epitaxy in the MBE system. Device design is made for CW operation in W-band. The material is investigated by inspection of beveled samples, defect etching, TEM, SIMS, and spreading resistance measurements. Double-drift flat-profile diodes are housed and mounted employing a technological procedure approved for single-drift diodes. For initial device characterization, dc measurements are performed. Information about doping profile, series, and thermal resistances is obtained. Preliminary RF measurements delivered a maximum output power of 600 mW at 94 GHz with 6.7-percent efficiency from an unoptimized structure.

Semiconductor Structures for 100 GHz Silicon IMPATT Diodes

Abstract: Single Drift double drift and quasi Read double drift (QRDDR) silicon IMPATT diodes for CW operation are compared. It is shown that for high power generation efficient semiconductor structures have to be developed. A theoretical design study predicts an efficiency of 14.1 % for the QRDDR diode at 94 GHz. Experimental investigations are performed with diodes the active layers of which are grown by Si-MBE. The results confirm the predicted differences between the structures: The QRDDR diodes deliver the highest efficiency (up to 11 %) and the highest output power: 910 mW.

90 GHz Single-Drift Impatt Diodes with High Output Power Level

Abstract: The increasing interest in solid state generators for millimeter wave application demands powerful devices. In the 90 GHz region up to now silicon impatt diodes exhibited the best performance. Purchasable cw-impatt diodes for W-band frequencies are normally double-drift diodes with output powers of 250 mW on copper heatsink and 500 mW on diamond heatsink (1,2). Leistner reached comparable values with single-drift diodes but in an open package with quartz stand offs (3).

Prospects of IMPATT devices based on wide bandgap semiconductors as potential terahertz sources

Abstract: In this paper the potentiality of impact avalanche transit time (IMPATT) devices based on different semiconductor materials such as GaAs, Si, InP, 4H-SiC and Wurtzite-GaN (Wz-GaN) has been explored for operation at terahertz frequencies. Drift–diffusion model is used to design double-drift region (DDR) IMPATTs based on different materials at millimeter-wave (mm-wave) and terahertz (THz) frequencies. The performance limitations of these devices are studied from the avalanche response times at different mm-wave and THz frequencies. Results show that the upper cut-off frequency limits of GaAs and Si DDR IMPATTs are 220 GHz and 0.5 THz, respectively, whereas the same for InP and 4H-SiC DDR IMPATTs is 1.0 THz. Wz-GaN DDR IMPATTs are found to be excellent candidate for generation of RF power at THz frequencies of the order of 5.0 THz with appreciable DC to RF conversion efficiency. Further, it is observed that up to 1.0 THz, 4H-SiC DDR IMPATTs excel Wz-GaN DDR IMPATTs as regards their RF power outputs. Thus, the wide bandgap semiconductors such as Wz-GaN and 4H-SiC are highly suitable materials for DDR IMPATTs at both mm-wave and THz frequency ranges.

A 90-GHz double-drift IMPATT diode made with Si MBE

Abstract: For the first time silicon double-drift IMPATT structures have been grown completely by Si molecular-beam epitaxy. The n-type layers are grown at 750 °C on low-resistivity n+-type substrates followed by p-type layers at 650 °C. The highly doped p+-layers are grown by solid-phase epitaxy in the MBE system. Device design is made for CW operation in W-band. The material is investigated by inspection of beveled samples, defect etching, TEM, SIMS, and spreading resistance measurements. Double-drift flat-profile diodes are housed and mounted employing a technological procedure approved for single-drift diodes. For initial device characterization, dc measurements are performed. Information about doping profile, series, and thermal resistances is obtained. Preliminary RF measurements delivered a maximum output power of 600 mW at 94 GHz with 6.7-percent efficiency from an unoptimized structure.

Si/SiGe MMIC's

Abstract: Silicon-based millimeter-wave integrated circuits (SIMMWIC's) can provide new solutions for near range sensor and communication applications in the frequency range above 50 GHz. This paper presents a survey on the state-of-the-art performance of this technology and on first applications, The key devices are IMPATT diodes for MM-wave power generation and detection in the self-oscillating mixer mode, p-i-n diodes for use in switches and phase shifters, and Schottky diodes in detector and mixer circuits. The silicon/silicon germanium heterobipolar transistor (SiGe HBT) with f/sub max/ values of more than 90 GHz is now used for low-noise oscillators at Ka-band frequencies. First system applications are discussed. >

CMOS on FZ-high resistivity substrate for monolithic integration of SiGe-RF-circuitry and readout electronics

Abstract: The choice of a highly resistive substrate for silicon millimeter-wave integrated circuits (SIMMWIC) imposed by the requirement of low RF-substrate losses requires the adaptation of a CMOS process on float zone silicon (FZ). A comparison of n- and p-channel devices realized on high resistivity substrate (p-type, 5000 /spl Omega//spl middot/cm) and standard CMOS substrates (CZ, n-type, 4-6 /spl Omega//spl middot/cm) is given. Using careful process design, we obtained device characteristics on FZ-substrates that are closely similar to those on standard material, thus allowing direct transfer of existing circuit designs.

Potentiality of IMPATT Devices as Terahertz Source: An Avalanche Response Time-based Approach to Determine the Upper Cut-off Frequency Limits

Abstract: Potentiality of Impact Avalanche Transit Time (IMPATT) devices based on different semiconductor materials such as InP, 4H-SiC, and Wurtzite-GaN (Wz-GaN) has been explored for operation at terahertz (THz) frequencies. Drift-diffusion model is used to design double-drift region (DDR) IMPATTs based on above mentioned materials at different millimeter-wave (mm-wave) and THz frequencies and the upper cut-off frequency limits of those devices are obtained from the avalanche response times at those mm-wave and THz frequencies. Results show that the upper cut-off frequency limits of both InP and 4H-SiC DDR IMPATTs are 1.0 THz; whereas, the same is 5.0 THz in Wz-GaN DDR IMPATTs. The Wz-GaN DDR IMPATTs emerge as the most suitable devices for generation of THz frequencies due to their small avalanche response time, high DC to RF conversion ratio, and sufficiently high RF power output at THz frequencies. But, it is observed that up to 1.0 THz, 4H-SiC DDR IMPATTs excel Wz-GaN DDR IMPATTs due to their higher ou...