摘要 |
The present invention relates to a method for etching a trench in a semiconductor substrate. More specifically, the present invention relates to a method for etching deep trenches such as those having aspect ratios of 30 and higher. According to embodiments of the invention, a method for etching a trench in a semiconductor substrate includes a first etch cycle wherein the trench is etched to a first depth. Thereafter, a protective liner is deposited on at least the upper part of the trench's sidewalls. The protective liner includes inorganic material. During at least one second etch cycle, the trench is etched to its final depth.
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