Preparation method of semiconductor device and semiconductor device

• Main Authors: MA YUE, YUAN JIAGUI, HE YUN
• Format: Patent
• Language: Chinese; English
• Published: 15.11.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention relates to a preparation method of a semiconductor device and the semiconductor device. The method comprises the following steps: forming a first groove in a first semiconductor material layer; forming an oxide layer, wherein the oxide layer covers the side wall and the bottom wall of the first groove and does not fill the first groove; the oxide layer comprises a first part located on the side wall of the first groove and a second part located on the bottom wall of the first groove; the first part is thicker than the second part; etching by taking the oxide layer as a mask layer, and removing a part of the first part, all the second part and a part of the first semiconductor material layer exposed by the second part, so that the bottom surface of the first groove extends downwards to form a second groove, and the line width of the second groove is smaller than that of the first groove; and doping a conductive material with a preset thickness into the first semiconductor material layer from the