| 摘要 |
<p>A manufacturing method of a semiconductor device is provided to increase the breakdown voltage of the high voltage transistor by decreasing the magnitude difference of impurity ion density. A manufacturing method of a semiconductor device comprises a step for forming a channel region; a step for forming a first trench; a step for performing an ion injection process; a step for forming a second trench(109). The channel region is formed at the substrate by using impurity ions. The tunneling insulating layer, a conductive film and a hard mask are successively formed on the top of the substrate. The first trench is formed on the substrate by passing through the tunneling insulating layer, the conductive film, and the fixed region of the hard mask. The ion injection process is performed through the first trench on the substrate by using the tunneling insulating layer, the conductive film and the hard mask as the ion mask. The second trench is formed on the substrate by using the tunneling insulating layer, the conductive film and the hard mask as the etching mask.</p> |
