Applied surface analysis in magnetic storage technology

This paper gives a synopsis of today's challenges and requirements for a su rface analysis and materials science laboratory with a special focus on mag netic recording technology. The critical magnetic recording components, i.e . the protective carbon overcoat (COC), the disk layer structure, the read/ write head including the giant-magnetoresistive (GMR) sensor, are described and options for their characterization with specific surface and structure analysis techniques are given. For COC investigations, applications of Raman spectroscopy to the structura l analysis and determination of thickness, hydrogen and nitrogen content ar e discussed. Hardness measurements by atomic force microscopy (AFM) scratch ing techniques are presented. Surface adsorption phenomena on disk substrat es or finished disks are characterized by contact angle analysis or so-call ed piezo-electric mass adsorption systems (PEMAS), also known as quartz cry stal microbalance (QCM). A quickly growing field of applications is listed for various X-ray analysi s techniques, such as disk magnetic layer texture analysis for X-ray diffra ction, compositional characterization via X-ray fluorescence, compositional analysis with high lateral resolution via electron microprobe analysis. X- ray reflectometry (XRR) has become a standard method for the absolute measu rement of individual layer thicknesses contained in multi-layer stacks and thus, is the successor of ellipsometry for this application. Due to the ongoing reduction of critical feature sizes, the analytical chal lenges in terms of lateral resolution, sensitivity limits and dedicated nan o-preparation have been consistently growing and can only be met by state-o f-the-art Auger electron spectrometers (AES), transmission electron microsc opy (TEM) analysis, time-of-flight-secondary ion mass spectroscopy (ToF-SIM S) characterization, focused ion beam (FIB) sectioning and TEM lamella prep aration via FIB. The depth profiling of GMR sensor full stacks was signific antly improved by the ToF-SIMS Cs method. (C) 2001 Elsevier Science B.V. Al l fights reserved.