Method for control of etch profile

摘要

A method for precisely controlling the profile of an opening etched in a layer of material, for example, an insulating layer. In one embodiment, wherein a silicon dioxide layer is reactive ion etched through a photoresist mask, the concentration of a reactive species in an etchant gas is changed during the etching process to change the slope of the opening, the upper sidewall portion of the opening having a shallow slope and the lower sidewall portion of the opening having a steep slope. The final slope of the opening formed by this method is independent of the initial slopes of the images developed in the photoresist mask.