| 摘要 |
<p>A semiconductor device and a fabricating method thereof are provided to protect a MOS transistor against overvoltage by forming a protection element having a junction region which breaks down a junction region of the MOS transistor eairlier. A MOS transistor(1) is formed in a semiconductor layer(3), and first junction regions(32,33) are formed between the semiconductor layer and diffusion layers included in the MOS transistor. A protection element is disposed around a formation region of the MOS transistor, and has second junction regions(34,35) having a junction breakdown voltage lower than that of the first junction region. Isolation regions(4,5) divide the semiconductor layer into plural regions and the MOS transistor is formed in one of the regions.</p> |
