Improvement of Rapid Thermal Oxide Quality by Anodization Compensation Technology

Abstract

With the progressive development of integrated circuits (IC) and the semiconductor industry, each step in semiconductor fabrication technology is becoming more and more important. The control of the processing step is related to the performance and reliability of semiconductor devices. Especially, the quality of the gate dielectric layer is extremely important to the reliability and electrical performance of ultra large scale integrated (ULSI) circuit. In this work, the rapid thermal oxidation followed by anodic oxidation (RTO+ANO) was proposed for the preparation of gate dielectric layers and was investigated.

To start with, the anodization and rapid thermal systems have been introduced along with the measurement system and the determination of the thickness of ultra-thin gate oxide. And then we introduce the growth models for DC anodization of silicon. The constant-frequency anodization (CF ANO), i. e., a positive DC voltage superimposed with an AC oscillation at a constant frequency, is used to repair the traps of the thermal ultra-thin gate oxide. A series of experiments were designed to observe the effects of anodic oxidation, the thermal oxidation time and growth temperature. Measurements of J-V and C-V curves were made to compare the electrical characteristics of devices studied.

We repeat the same studies with additional post oxidation anneal (POA) treatment. From the C-V and J-V curves, The effects of anodic oxidation and POA treatment can be observed. Finally, conclusions and some other suggestions about this thesis were given.