表面无小丘Al双层栅电极结构研究

Study on Hillock-Free Al Gate Materials with Double Layer Structure

利用ＤＳＣ方法研究了纯铝薄膜中的小丘现象，同时制备了Ａｌ双层栅电极Ｔａ／Ａｌ、Ｃｒ／Ａｌ和Ｍｏ／Ａｌ薄膜，并在不同温度下进行了退火处理，研究了双层结构中上层金属（Ｔａ、Ｃｒ和Ｍｏ）厚度对Ａｌ薄膜中小丘的抑制作用。实验结果表明，上层Ｔａ膜厚度在８０～９０ｎｍ左右（在本实验条件下）时，可得到表面无小丘的Ｔａ／Ａｌ薄膜栅材料。实验制备的表面无小丘 Ｔａ／Ａｌ、 Ｃｒ／Ａｌ和 Ｍｏ／Ａｌ等栅电极材料的电阻率均在 ７～２０μΩ·ｃｍ之间，基本满足现今对角线为 ２５～５１ｃｍ（１０～２０ｉｎ）大屏幕、高清晰度ＴＦＴ ＬＣＤ要求。

The hillock phenomenon in pure-Al thin films was investigated by DSC method, then the Al-gate electrodes with double layer structure, such as Ta/Al, Cr/Al and Mo/ Al thin films, were prepared, and the isothermal annealing treatment were carried out under the conditions of different temperatures in the experiment. The restrain effect of the different thickness of upside metals (such as Ta, Cr and Mo) on the hillock in Al film was studied. The experimental results show that the hillock-free gate line material of Ta/Al thin film can be required when the thickness of Ta film on the Al film is 80- 90um. The resistivities of all hillock-free gate materials, including Ta/Al, Cr/Al and Mo/Al prepared in this experiment, are 7-20μΩ·cm. At present, they satisfy the application on the 10-20 inch TFT LCD with large screen, high definition displays.