尺寸缩小对沟槽MOSFET性能的影响

Effect of Scalling Down on the Characteristic of Trench MOSFET

介绍了沟槽MOSFET(TMOS)的器件特性。为获得更小的Rdson(导通电阻)·A(面积)值,讨论了在元胞间距尺寸缩小到1.4μm时,由于制造工艺的局限性以及沟道长度变短、结深变浅后,器件穿通风险加大。提出在不增加掩模版的前提下通过优化工艺,利用突起式结构以及沟槽式接触技术克服这一潜在风险,最终通过试验验证,得到了高稳定性低导通电阻的低压TMOS。

The characteristic of trench MOSFET was introduced. In order to achieve the smaller Rdson Area value, the pitch size was scaled down to 1.4 μm. Meanwhile, the high risk of punch-through due to process limitation was described when channel length became smaller and source junction became shallower. Then the solution by using the poly stickup structure and trench contact technology without any extra mask was demonstrated to avoid those potential risks. At last, the low-voltage power trench MOSFET is successfully proved to get the highly stable performance and low specific-on-resistance.