Self-aligned inversion channel In<inf>0.53</inf>Ga<inf>0.47</inf>As N-MOSFETs with ALD-Al<inf>2</inf>O<inf>3</inf> and MBE-Al<inf>2</inf>O<inf>3</inf>/Ga<inf>2</inf>O<inf>3</inf>(Gd<inf>2</inf>O<inf>3</inf>) as gate dielectrics

Abstract

Self-aligned inversion-channel In _0.53 Ga _0.47 As n-MOSFETs with ex-situ atomic-layer-deposited Al ₂ O ₃ and in-situ ultra-high-vacuum deposited Al ₂ O ₃ /Ga ₂ O ₃ (Gd ₂ O ₃ ) as gate dielectrics have been demonstrated. Both devices exhibit excellent DC characteristics, including high drain currents and transconductances. In addition, RF characteristics of both devices were analyzed; without using any isolation, non dc-embedded current gain cutoff frequency (f _T ) and maximum oscillation frequency (f _max ) of ~ 3.1 and 1.1 GHz (ALD-Al ₂ O ₃ ) and of ~ 17.9 and 11.2 GHz (MBE-Al ₂ O ₃ /Ga ₂ O ₃ (Gd ₂ O ₃ )), respectively, have been obtained.