Sub‐Micron thick Step‐Graded AlGaN Buffer on Silicon with a High Buffer Breakdown Field

Submicrometer‐thick AlGaN/GaN high‐electron‐mobility transistor (HEMT) epilayers grown on silicon substrate with a state‐of‐the art vertical buffer breakdown field as high 6 MV cm −1 enabling voltage of 250 V for short gate‐to‐drain distances despite such thin structure are reported. HEMTs gate length 100 nm exhibit good DC characteristics low drain‐induced barrier, going mV DS 30 V. Breakdown voltages each epilayer from the decomposed heterostructure reveals that outstanding strength is attributed to insertion Al‐rich AlGaN in layers combined an optimized AlN nucleation layer. As result, large signal measurements at 10 GHz could be reliably achieved up = 35 use length. These results demonstrate potential submicrometer‐thick GaN‐on‐Si heterostructures high‐frequency applications.