Preparation method of semiconductor device

• Main Authors: FAN JIANGUO, SHEN JIANFEI, JI FENGQIANG
• Format: Patent
• Language: English
• Published: 11.02.2015
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention discloses a preparation method of a semiconductor device. The preparation method of the semiconductor device comprises the following steps: firstly providing a semiconductor substrate, wherein the semiconductor substrate is provided with a shallow trench; then performing ion implantation on the bottom of the shallow trench; finally forming a liner oxide layer on the bottom and the side wall of the shallow trench. According to the preparation method of the semiconductor device, ion implantation is performed on the bottom of the shallow trench so as to form a doping region on the bottom of the trench shallow, and the growth speed of the liner oxide layer in the doping region is greater than that of the liner oxide layer on the side wall of the shallow trench, so that in the finally formed liner oxide layer, the bottom thickness of the liner oxide layer is obviously improved, further the uniformity of the bottom thickness and the sidewall thickness of liner oxides in shallow trench isolation is increased, current leakage of shallow trench isolation is prevented, and thus the electrical property of a shallow trench isolation device is improved.