Title :
Improved Electrical Characteristics of Ge MOS Devices With High Oxidation State in
Interfacial Layer Formed by
In Situ Desorption
Author :
Chen-Chien Li ; Kuei-Shu Chang-Liao ; Li-Jung Liu ; Tzu-Min Lee ; Chung-Hao Fu ; Ting-Ching Chen ; Jen-Wei Cheng ; Chun-Chang Lu ; Tien-Ko Wang
Author_Institution :
Dept. of Eng. & Syst. Sci., Nat. Tsing Hua Univ., Hsinchu, Taiwan
Abstract :
Ge MOS devices with about 95% Ge4+ in HfGeOx interfacial layer are obtained by H2O plasma process together with in situ desorption before atomic layer deposition (ALD). The equivalent oxide thickness is scaled down to 0.39 nm; the leakage current is decreased as well. The improvement can be attributed to the in situ Ge suboxide desorption process in an ALD chamber at 370 °C. The interface trap density and frequency dispersion need further process development to be reduced.
Keywords :
MOS capacitors; atomic layer deposition; desorption; elemental semiconductors; germanium; hafnium compounds; interface states; leakage currents; oxidation; plasma materials processing; Ge; Ge MOS devices; H2O plasma process; HfGeOx; HfGeOx interfacial layer; atomic layer deposition; electrical characteristics; equivalent oxide thickness; frequency dispersion; high oxidation state; in situ Ge suboxide desorption process; interface trap density; leakage current; temperature 370 degC; Hafnium compounds; Leakage currents; Logic gates; MOS devices; Oxidation; Plasmas; Water; Ge MOS; GeO; desorption; desorption.; in situ;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2014.2310636