3results about How to "Decreases bowing profile" patented technology

An etching method in which bowing or lateral etching is reduced or minimized, particularly with respect to bowing which can occur in etching of an oxide layer in high aspect ratio structures. It has been recognized that such bowing typically occurs in the upper portion of the oxide layer in terms of its location, but that the timing at which the bowing occurs is during the etching of the lower regions of the oxide layer and also during etching of a poly-Si or SOI layer located under the oxide layer. In a preferred form, a thicker passivation layer is formed in the upper region of the oxide layer and a thinner passivation layer is formed when etching the lower portion of the oxide layer or deeper in the etch trench. As a result, reduction in the passivation layer in the upper region which can occur during etching of the lower or deeper region of the trench can be accommodated by the increased thickness passivation layer. In addition, the bowing can be additionally reduced by accelerating the poly-Si or SOI etch, for example, by poly-Si simultaneously using both argon and nitrogen during the etch.