Papers by Keyword: Wafer Polishing

Abstract: The polishing is one of the important methods in manufacturing of silicon wafer and in thinning of completed device wafer. Generally, getting a flat surface such as a mirror is the purpose of the process. The wafer surface roughness is affected by many variables such as the characteristics of the carrier head unit, operation, speed, the pad and slurry temperature. Optimum process conditions for experimental temperature, down-force, slurry ratio are investigated, time is used as a fixed factor. This study will report the evaluation on surface of wafer by dependent of varying platen, chuck rpm, temperature variation, and oscillation which affect it has on the surface roughness. In this experiment, it is determined the optimum condition for polishing silicon wafers. By using optimum condition, it helps to achieve an ultra precision mirror like surface.

Abstract: The polishing process of a silicon wafer is a critical factor in the fabrication of semiconductor. Because a globally planar and mirror-like wafer surface are achieved in this process. The surface roughness in the wafer depends on the surface properties of the carrier head unit along with other machining conditions such as working velocity, polishing pad, temperature, down-force, etc. In this paper, the wafer surface is investigated according to several parameters and experimental data. Experiments were performed to observe the down-force and temperature when the wafer carrier head unit was pressed down onto the polishing pad. A loadcell was employed to obtain the signal of the applied pressure against the polishing pad. Also, working temperature was detected using an infrared sensor. To study on the optimum conditions of machining, monitoring system is coded in Ch and the results of experiment present data using Ch.

Abstract: The purpose of this study is to reveal the mechanism of wafer touch polishing by high purity colloidal silica slurry containing organic surfactants such as HEC (hydroxyl-ethyl cellulose). The effect of surfactant concentration on wafer touch polishing was studied with the aim of improving roughness on wafer surface after polishing. As a result, the level of haze and micro-roughness are decreased with the decrease of surfactant concentration.