Low frequency and microwave characterization of submicron-gate In0.52Al0.48As/In0.53Ga0.47As/In0.52Al0.48As heterojunction metal-semiconductor field-effect transistors grown by molecular-beam epitaxy

Abstract

Doped-channel i-In0.52Al0.48As/n+-In0.53Ga0.47 As/i-In0.52Al0.48As heterojunction metal-semiconductor field-effect transistors lattice matched to the InP substrates with gate lengths in the submicron range have been fabricated and characterized. The dc and microwave performance of the devices are presented in this paper. Drain current anomalities, or the kink effects, were observed at room temperatures as well as at 77 K in the dc measurements. The kinks are associated with the deep-level electron trapping, and are not present at microwave frequencies. The dc and microwave bias points for achieving maximum transconductance are different. Normal microwave characteristics are exhibited. A compression of transconductance gm is observed in the dc measurement, while such gm degradation phenomenon does not appear at microwave frequencies. At 10 GHz, an extrinsic gm of 507 mS/mm, a current-gain-cutoff frequency ft of 49.5 GHz, and a power-gain-cutoff frequency (fmax) of 70.5 GHz were observed for a 0.25-μm-gate device. For a 0.3-μm-gate device, a gm of 545 mS/mm, an ft of 42 GHz, and an fmax of 114 GHz were measured. Output conductance as low as 7.7 mS/mm was measured. A voltage gain (gm/gds) as high as 64 was observed. The voltage gain for measured devices is well above 20 for a wide range of bias conditions. Fabricated devices show their potential for high-frequency operations. Further investigation of the origin of traps should result in improved low-frequency device characteristics.

Defect-related luminescence in InAlAs on InP grown by molecular beam epitaxy

“…The In x Al 1−x As III-V semiconductor alloy has long been established as an important material in both fundamental studies of III-V properties and in a wide range of applications. The ability to lattice-match the InP substrate and In y Ga 1−y As alloy allowed the creation of unstrained heterostructures for field effect and bipolar transistors, as well as optoelectronic applications, including light emitters and photodetectors for communication ranges of the spectrum [1][2][3][4]. The properties of the alloy material grown by wellestablished techniques matched the requirements posed by these applications.…”