Using Spike-Anneal to Reduce Interfacial Layer Thickness and Leakage Current in Metal–Oxide–Semiconductor Devices with TaN/Atomic Layer Deposition-Grown HfAlO/Chemical Oxide/Si Structure

Abstract

In this study, the characteristics of Ta/chemical SiO 2 /Si devices with their chemical oxides formed by various chemicals, including HNO 3 , SC1, and H 2 SO 4 +H 2 O 2 solutions, were first investigated. We found the HNO 3 split depicts the lowest leakage current and the best hysteresis behavior. Next, chemical oxide formed by HNO 3 was applied to form the interfacial SiO 2 layer for metal-oxide-semiconductor (MOS) devices with Ta/HfAlO/chemical SiO 2 /Si structrue. The effects of a hightemperature spike anneal were then studied. We found that the spike-anneal process can effectively reduce the thickness of the chemical oxide from 10 to 7 Å , thus is beneficial in preserving the low effective oxide thickness (EOT) of the structure. Furthermore, both the gate leakage current and stress-induced leakage current (SILC) were also effectively suppressed by the high-temperature spike-anneal.