Record Breakdown Voltage (2200 V) of GaN DHFETs on Si With 2- Buffer Thickness by Local Substrate Removal

摘要

In this letter, we present a local substrate removal technology (under the source-to-drain region), reminiscent of through-silicon vias and report on the highest ever achieved breakdown voltage $(V_{rm BD})$ of AlGaN/GaN/AlGaN double-heterostructure FETs on a Si (111) substrate with only 2-$muhbox{m}$-thick AlGaN buffer. Before local Si removal, $V_{rm BD}$ saturates at $sim$700 V at a gate–drain distance $(L_{rm GD}) geq hbox{8} muhbox{m}$. However, after etching away the substrate locally, we measure a record $V_{rm BD}$ of 2200 V for the devices with $L_{rm GD} = hbox{20} muhbox{m}$ . Moreover, from Hall measurements, we conclude that the local substrate removal integration approach has no impact on the 2-D electron gas channel properties.