The most frustrating type of head crash is one that wipes out data on one track after thousands of hours of stable operation. Analysis of debris gives few clues as to its cause. This paper explains this type of head crash and identifies the liquefaction of organic gases on the taper section of the head slider as its primary cause. Both theoretical considerations and experimental results are presented.
Cleaning is one of the most important processes in mask making, because it decides final quality. In cleaning process, it is necessary for reticle cleanliness to not only remove particles from reticle but also prevent adsorption and re-deposition onto reticle. There is the knack for reticle cleaning, and we introduce three keys in this paper. The first key is the rinse after chemical treatment. By the rinse sequence modification, the cleaner was refined and the particle removal ability was improved. The second key is quality control to grasp the situation of cleaner. By the daily check, cleaner's abnormal condition is found at an early stage, quick action is taken, and then stable cleaning quality is kept every day. And the third key is proper choice of cleaners. We have adopted pre-cleaning process and selected the adequate cleaner for each cleaning level and improved cleaning yield and quality.
Cleaning of PSM is one of the most important technology for the development and production of quarter micron devices. In cleaning of PSM, it is needed not only to remove the particles on shifter and quartz, but also not to change the phase angle and the transmittance. For this purpose, new technology of PSM cleaning has been developed. Through the cleaning of 'MoSiON- halftone,' effectiveness of our techniques is shown.
Three cleaning methods were examined to check their strong points. Cleaning results were analyzed from the aspects on removal of particles and chemicals. Starlight inspection results showed that conventional wet cleaning based on chemicals, such as H2SO4 and NH4OH, could remain small particles on chrome-oxide (CrOX). DUV irradiation could assist this traditional SC-1 (mixture of NH4OH and H2O2 and HH(subscript 2O) cleaning in removing these sticking particles. Electrolyzed water, contained anode and cathode water, showed same tendency as SC-1 treatment, which could easily attract particles to CrOX surface. Mechanism of particle removal and attraction was considered from the aspect on electrostatic reaction between particles and photomask surface. ArF ((lambda) =193nm) lithography could cloud quartz surface with crystallized substances. Analytical results implied that they had been generated by optical-chemical reaction between ArF light and chemical residue after cleaning. Experimental results showed that DUV treatment before cleaning was effective to prevent reticle surface from chemical contamination. From the above knowledge, suggestion about reticle cleaning process for ArF lithography is described as a conclusion.
Using computer simulation, the flying characteristics of a conventional positive pressure head slider and two types of zero-load negative pressure head sliders are compared. One of the negative pressure head sliders is aimed at high stiffness (HS type), and the other is at CSS durability by virtue of its fast taKe-off design (FTO type). The reverse step of the FTO is deeper than that of the HS type. On the FTO type, suction increases gradually as the disk speed increases, and the slider takes off at a lower velocity than the HS type. So the suction of the FTO type is still low when the slider takes off from the disk. By experiment, we confirmed that the FTO prototype head impacts little on the medium during CSS, and also has superb flying stability.
Abstract Chromium microparticles (20-100 nm) were prepared by 248– nm laser irradiation of deaerated aqueous solutions of chromium (II) dichloride in the presence of sodium formate and sodium polyphosphate, followed by aging. The microparticles transferred onto a silicon substrate were melted by 193– nm laser irradiation. The microparticles on a silicon substrate could be almost completely removed by 308– nm irradiation at the fluence of 0.5 J cm−2 pulse−1.
Heads for high-performance disk storage must be able to withstand an acceleration of dozens of G-force and be capable of positioning to submicron precision. A measuring technique that can totally analyze the flight stability and access ability of the slider was developed. It involves three-dimensional modal analysis of the suspension using a laser Doppler anemometer, a laser Doppler vibrometer, and simultaneous measurement of spacing fluctuation. Using this system to examine an inline head, it was found that notable lateral and torsional modes of the suspension vibration were caused by the access acceleration of the rectangular wave, and that there is pronounced spacing fluctuation. In addition, these lateral vibrations cause the pivot to slip, which may cause problems in high-speed head access.< >
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