Patent ID: 7418921
Filing Date: 2008-09-02
Classification: C23C

Abstract:
1. A plasma CVD apparatus for forming a thin film on a wafer, comprising: a reaction chamber; a susceptor for placing the wafer thereon installed inside the reaction chamber and having a convex-concave surface comprising an inner annular convex portion and an outer annular convex portion which are concentrically formed, wherein the inner annular convex portion is configured to support the wafer at a portion between a center and a periphery of the wafer, and the outer annular convex portion is configured to support the wafer at its periphery; and a shower plate for discharging a gas therethrough installed inside the reaction chamber substantially parallel to and facing the susceptor for generating a plasma therebetween, said shower plate having a convex-concave surface configured by a convex equation L which is a function of a radius R, on which a secondary equation M is overlaid, wherein the equation M is a function of a radius R and comprised of a concave equation at a central area and a convex equation at a peripheral area, wherein the convex-concave surface of the shower plate comprises an inner annular protrusion formed between an area defined by the concave equation and an area defined by the convex equation in the equation M, and an outer annular protrusion formed and defined by the convex equation in the equation M, wherein respective locations of the inner annular convex portion and the outer annular convex portion of the susceptor defined using a radius R are overlapped with respective locations of the inner annular protrusion and the outer annular protrusion of the shower plate defined using a radius R.