[New design of Grimm-type glow discharge source for real-time sputtered depth measurement]

The crater depth value of sample surface during sputtering is important analysis information for the depth profile analysis of glow discharge spectrometry. Real-time sputtered depth measurement with Laser triangulation measurement method for glow discharge compositional analysis, effectively solves the issues of incorrect depth value calculation and complicated procedures in traditional depth analysis method. This paper presents a new Grimm-type glow discharge source for real-time sputtering depth measurement by laser displacement sensor. This GD source also ensures fine sputtering effects and ideal resolution for multi-layer structure and interface. Optical fiber is used to transmit glow spectrum signal from GD-source to multi-channel photoelectric detection system. The design for the first time accomplishes the real-time signal collection and time-based synchronization analysis for both spectrum signal and sputtering depth signal. The real-time sputtering depth measurement curve of standard samples is obtained. The design and operating principle of this new-type GD-source is described in detail. Under the sputtering conditions of 30 mA, 900 V and 20 minutes, the sputtering rates of iron-based and copper-based sample sputtered by this GD source with good depth resolution are about 10 and 55 nm x s(-1). Surface topography picture of sputtering crater and microphotograph of metal samples are provided in the paper. Low-alloy steel standard sample is tested with this new GD source, the relative standard deviation (RSD) of C, Cu, Al, Ni, Mo, Mn and V elements are less than 1.7%, while for Cr and Si elements RSDs are less than 2.6%. The result data of the testing is provided in this paper.