Y.M. Tong

Large area high quality diamond film deposition by high power DC arc plasma jet operating at gas recycling mode

Abstract Principles of a high power DC arc plasma torch with rotating arc roots and the semi-closed gas recycling system are presented. Recent results on large area high quality free standing diamond film deposition by a high power DC arc plasma jet CVD system operating at gas recycling mode is discussed. It was shown that the uniformity of diamond film deposition over a large substrate area was closely dependent on the uniformity and symmetry of the plasma, which can be adjusted by proper manipulation of the magnetic field and the effects of fluid dynamics. Effect of gas recycling on the quality of diamond films is discussed. By proper design of the whole system and process optimization, thick uniform diamond wafers of Φ60–110 mm in diameter with a thickness up to 2 mm and transparent diamond wafers of Φ30–60 mm in diameter has been deposited successfully. It is demonstrated that gas recycling can be used even for high quality diamond film synthesis. This is of technical and economical importance in the development of high power DC arc plasma jet CVD systems for economical fabrication of high quality diamond wafers.