유도결합 플라즈마 스퍼터링 장치에서 MgO의 반응성 증착 시 공정 진단

Abstract

Process analysis was carried out during deposition of MgO by inductively coupled plasma assisted reactive magnetron sputtering in Ar and O2 ambient. At the initiation of Mg sputtering with bipolar pulsed dc power in Ar ambient, total pressure showed sharp increase and then slow fall. To analyse partial pressure change,QMS was used in downstream region, where the total pressure was maintained as low as 10−5 Torr during plasma processing, good for ion source and quadrupole operation. At base pressure, the major impurity was H2O and the second major impurity was CO/N2 about 10%. During sputtering of Mg in Ar, H2 soared up to 10.7% of Ar and remained as the major impurity during all the later process time. When O2 was mixed with Ar, the partial pressure of Ar decreased in proportion to O2 flow rate and that of H2 dropped down to 2%. It was understood as Mg target surface was oxidized to stop H2 emission by Ar ion sputtering. With ICP turned on, the major impurity H2 was converted into H2O consuming O2 and C was also oxidized to evolve CO and CO2.