Improved breakdown voltage and RF characteristics in AlGaN/GaN high-electron-mobility transistors achieved by slant field plates

Abstract

We experimentally demonstrate the efficacy of using slant field plates (field plates with the plate-to-channel gap gradually increasing away from the gate edge) on the breakdown voltage. We develop a new fabrication process using a multi-step SiCN film such that both slant and conventional field plates are fabricated simultaneously. Consequently, we fabricate 230-nm-gate AlGaN/GaN HEMTs with several types of field plates. The slant field plate increases the breakdown voltage by 66% more than that of the conventional field plate. The advantages of using slant field plates to increase the breakdown voltage are experimentally confirmed for the first time.

A new process approach for slant field plates in GaN-based high-electron-mobility transistors

“…The dry etching properties of the deposited film, such as etching rate, depend on these carrier gases. 13,14) As a result, the carrier gas profile affects the cross-sectional shape when the SiCN film is etched. This will be discussed in Sect.…”

“…Recently, we have developed slant FPs using multistep SiCN that enables us to perform a systematic experiment to prove the advantage of slant FPs over conventional FPs. 13,14) More recently, Corrion et al has been reported both a source-connected slant FP 15) and a gateconnected slant FP. 16) They also proved the advantage of slant FPs in terms of reduced dynamic on-state resistance and gate capacitance.…”

High breakdown voltage AlGaN/GaN HEMTs with a dipole layer for microwave power applications

“…In general, the technique of multiple field plates (FP) is adopted to manage the distribution of surface electric field in GaN HEMTs [2,3]. However, the processing of multiple FP is difficult [2][3][4] and FP structure will increase the parasitic capacitance, which results in the degradation of high-frequency performance of the device [5,6]. In addition, doping Fe/C in GaN buffer layer [7,8] is also one of the feasible solutions for breakdown enhancement.…”

Achievement of balanced high frequency and high breakdown by InGaAs-based high-electron-mobility transistors with slant field plates

“…For GaNbased HEMTs, many research groups reported improvements in BV using FPs. [7][8][9][10][11][12][13][14] In particular, the use of a slant FP is reported as the most effective way of reducing the maximum electric field at the gate edge. [8][9][10][11][12][13][14] The advantage of the slant FP over the conventional FP was studied theoretically 9,10) and experimentally [11][12][13][14] For GaN-based HEMTs.…”

“…[7][8][9][10][11][12][13][14] In particular, the use of a slant FP is reported as the most effective way of reducing the maximum electric field at the gate edge. [8][9][10][11][12][13][14] The advantage of the slant FP over the conventional FP was studied theoretically 9,10) and experimentally [11][12][13][14] For GaN-based HEMTs. Kobayashi et al reported the fabrication of slant FPs using a multistep SiCN film and demonstrated for the first time increased BV in comparison with that using conventional FPs.…”