Optimization of Etching Uniformity for Multi-Wafer Dry Etch Equipment

Wafer-to-wafer uniformity is a key parameter to evaluate processing quality of multi-wafer production equipment in IC manufacturing process.Using orthogonal test method,experiments of SiO2 etching were made on a dry etch machine with a capacity of 18 pieces of 150-mm wafers.Better combination of factors affecting wafer-to-wafer uniformity of dry-etch process was obtained by intuitive analysis.Significance and credibility of effects of factors on wafer-to-wafer uniformity were obtained by analysis of variance.Principles to select levels of factors and optimized process conditions for targeted wafer-to-wafer uniformity in dry etch process were obtained by comprehensive technology analysis.Wafer-to-wafer uniformity using optimized process was measured to be 3.93%.The orthogonal test and analysis method are also applicable for process optimization of other multi-wafer and single-wafer production equipments.