Investigation of heat-dissipation structures in resonant tunneling diodes and their characteristics on terahertz oscillators

Abstract

This study investigates the heat dissipation structures for resonant tunneling diodes (RTDs). The n+-InGaAs conductive layer beneath the RTD double-barrier layer, possessing low thermal conductivity and disrupting heat dissipation, has been replaced with n+-InP, which has high thermal conductivity. We manufactured simple RTD mesa structures with varying areas to analyze the impact of heat dissipation. Additionally, we conducted a study to explore the relationship between mesa area and power consumption at the RTD mesa under current-voltage measurements. The results clearly indicate that the proposed structure, incorporating an n+-InP layer, can function over an area twice as large without experiencing heat-induced destruction. Employing this proposed structure, we successfully fabricated terahertz oscillators equipped with rectangular-cavity resonators. These oscillators achieved relatively high output power, approximately 0.2 mW was achieved at a frequency of 0.53 THz, all without any heat-induced damage, even within a large-area RTD device.

Fundamentals and recent advances of terahertz resonant tunneling diodes

“…To address this problem, we proposed alternative structures that replace the conductive layer with n + -InP, which has a much higher thermal conductivity of 68 W m −1 •K −1 . 84) We experimentally measured the yield rate versus the mesa area for RTDs with three different bottom conductive layer configurations, as shown in Fig. 14.…”

“…3.2 was proposed. 84) This resulted in an output power of 0.2 mW at 500 GHz with large-area RTDs of ∼10 μm 2 without heat destruction. Most recently, through continuous device optimization, the output powers of cavitytype oscillators have been improved to exceed 1 mW in the 600-700 GHz range.…”

Terahertz resonant-tunneling-diode oscillator with two offset-fed slot-ring antennas

“…The conduction layer under the RTD layer incorporates n + -InP, which has a high thermal conductivity, to improve heat dissipation. 31) Figure 4(a) shows a microphotograph of the fabricated device, and Fig. 4(b) shows a scanning electron microscopy (SEM) image of the RTD and air-bridge structure.…”