A new sputtering-type electron cyclotron resonance microwave plasma using an electric mirror and high-rate deposition

Abstract

Film deposition is performed by means of a new electron cyclotron resonance microwave plasma employing a high-rate sputtering system using an electric mirror. This apparatus consists of both planar and cylindrical targets. The magnetic flux penetrates both target surfaces. Microwave power is perpendicularly or obliquely introduced into the resonance cavity. High-density plasma, exceeding 1012 cm−3, much denser than the cutoff density 7×1010 cm−3, is generated. The electron beam oscillating between the two targets plays a major role in generating the dense plasma, i.e., as a beam plasma interaction. Both insulator and conductor films can be deposited continuously by this new sputtering method at high rates under low gas pressures of 10−2 . Al, Mo, and Fe films are deposited at rates above 2000 Å/min. Target utility reaches higher than 55% for nonmagnetic materials including Mo and Al, and 40% for magnetic materials including Fe. Film thickness uniformity over 4 in. in diameter with a 10% distribution is realized.