Plasma enhanced chemical vapor deposition apparatus

Abstract

This invention provides a plasma-enhanced chemical vapor deposition (PECVD) apparatus. The apparatus includes a cavity, an RF power supply located outside the cavity for generating an excitation plasma RF signal, a gas distribution plate assembly located inside the cavity and below the gas inlet for uniformly distributing the reactant gas into the cavity from the gas inlet, an upper electrode located below the gas distribution plate assembly with a concave bottom surface, an electrode shielding layer suspended below the upper electrode, and a lower electrode located at the bottom of the cavity, grounded, and opposite to the upper electrode. The electrode shielding layer includes multiple dielectric units and multiple metal units. During the PECVD process, the plasma density fluctuation in the regions corresponding to the multiple dielectric units and multiple metal units does not exceed a predetermined range. This invention improves plasma distribution uniformity and film uniformity.

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