一种使沟槽侧角圆滑的新颖STI工艺

Novel Corner Rounding Process for Shallow Trench Isolation

介绍了一种使沟槽侧角圆滑的STI工艺技术,该技术在沟槽腐蚀完,通过湿法工艺去除部分氮化硅(Nitride Pull back),再正常生长线性氧化层,使槽的侧角更加圆润光滑,同时减小了沟槽Divot深度。该工艺避免了附加高温热过程所导致的缺陷扩散和膜应力增大问题,现已成功应用于0.13μm逻辑工艺。采用该工艺完成的器件,反窄沟道效应明显减弱,窄沟器件的漏电有效降低。

A new STI （Shallow Trench Isolation） comer rounding process is proposed. The process removes parts of SIN by wet method after STI etch and grows linear oxide. Highly controlled comer rounding radius and small divot depth is achieved without high temperature oxidation process. Thus it is free from defects and undesirable stress. And now this process is applied to 0.13 μm logic process. The current leakage due to parasitic comer transistors of STI structure is effectively reduced and the reverse narrow channel effect is suppressed clearly.