氮化銦鋁/氮化鋁/氮化鎵金屬-氧化物-半導體異質結構場效電晶體之光電特性研究

Abstract

本專題旨在藉由超音波霧化熱裂解法研製具有氧化鋁閘極介電層之氮化銦鋁/氮化鋁/氮化鎵金屬-氧化物-半導體結構異質結構場效電晶體，使用高k值閘極介電層改善閘極絕緣能力與獲致鈍化表面缺陷效果，以提升元件工作性能以及提升元件崩潰特性。 為提供相關特性比較，本研究同時研製具有傳統蕭特基閘極平面結構、具有氧化鋁閘極介電層結構之氮化銦鋁/氮化鋁/氮化鎵金屬異質結構場效電晶體，所獲致之直流特性分別為：最大汲極-源極電流密度 IDS,max（544.2 mA/mm、810.4 mA/mm），無閘極偏壓飽和電流密度IDSS0（291.1 mA/mm、331.3 mA/mm），最大外質轉導gm,max（ 221.2 mS/mm、180.4 mS/mm），閘極漏電流Ig（1.4×10-2 mA/mm、1.1×10-6 mA/mm），閘極-汲極關閉狀態崩潰電壓BVGD（-126 V、-185.5 V），功率轉換效益P.A.E.（16.5%、26.3% V）。實驗結果顯示本研究所研製具有氧化鋁閘極介電層之氮化銦鋁/氮化鋁/氮化鎵金屬-氧化物-半導體結構異質結構場效電晶體，能有效改善元件直流特性，以及具有高k值閘極介電層改善閘極絕緣能力與獲致鈍化表面缺陷效果可提升元件的崩潰特性，此外，本篇專題亦有使用紫外線檢測技術研究光電特性。

Ultraviolet (UV) detection and electrical characteristics of In0.17Al0.83N/AlN/GaN metal–oxide–semiconductor heterostructure field-effect transistors (MOS-HFETs) with Al2O3 gate-dielectric and passivation formed by using ultrasonic spray pyrolysis deposition (USPD) are studied with respect to a conventional Schottky-gate HFET. Due to the enhanced gate control, the DC characteristic of device has been effectively improved. Depositing the high-k aluminum dioxide as a gate-dielectric layer, the gate leakage reduced by gate insulation and surface passivation. Providing the comparison of the characteristics, In this thesis, Schottky-HFET, Al2O3-MOS-HFET, have been achieved, including maximum drain-source saturation current density (IDS, max) of 544.2 mA/mm, 810.4 mA/mm, , drain-source current density at VGS = 0 V (IDSS0) of 291.1 mA/mm, 331.3 mA/mm, maximum extrinsic transconductance (gm, max) of 212.2 mS/mm, 180.4 mS/mm, gate leakage current (Ig) at VGS = -10 V of sample A and sample B were 1.4×10-2 mA/mm, 1.1×10-6 mA/mm, two-terminal off-state gate-drain breakdown voltage (BVGD) of -126 V, -185.5 V, and power-added efficiency (P.A.E.) of 16.5%,26.3% at 2.4 GHz, respectively, at 300 K. From the experiment results, the superior performance of Al2O3 metal-oxide-semiconductor HFETs (MOS-HFET) can be effectively improve DC characteristics by USPD technique, not only decrease leakage current but increase breakdown voltage of device.