Papers by Author: Jong Koo Won

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: Polishing is one of the important methods in manufacturing of Si wafers and in thinning of completed device wafer. This study will report the evaluation on abrasion of wafer according to processing time; machining speed and pressure which have major influence on the abrasion of Si wafer polishing, for this, this study design the head unit and analysis head unit. After that, apply to experiment. It is possible to evaluation of wafer abrasion by load cell and infrared temperature sensor. The evaluation of abrasion according to processing condition is selected to use result data that measure a pressure, machining speed, and the processing time. This result is appeared by abrasion in machining condition. Through that, the study cans evaluation a wafer abrasion in machining. It is important to obtain mirror-like wafer surface.

Abstract: It is important to obtain the optimal condition in wafer polishing processing. Polishing is one of the most important methods in manufacturing of Si wafers and in thinning of completed device wafer. This study will report the evaluation on abrasion of wafer according to processing time; machining speed and pressure which have the major influence on the abrasion of Si wafer polishing, for this, this study design the head unit and analysis head unit. After that, this study applies to experiment. The evaluation of abrasion according to processing condition is selected to use result data that measure a pressure, machining speed, and the processing time. This result is appeared by machining condition. Through that, the study can evaluate the abrasion characteristic of wafer in machining.

Abstract: As the level of Si-wafer surface directly affects device line-width capability, process latitude, yield, and throughput in fabrication of microchips, it needs to have ultra precision surface and flatness. Polishing is one of the important processing having influence on the surface roughness in manufacturing of Si-wafers. The surface roughness in wafer polishing is mainly affected by the many process parameters. For decreasing the surface roughness, the control of polishing parameters is very important. In this paper, the optimum condition selection of ultra precision wafer polishing and the effect of polishing parameters on the surface roughness were evaluated by the statistical analysis of the process parameters.

Abstract: This study presents the development of an ultra-precision grinding system based on a new grinding technique called the “In-Process Grinding Method (IPGM)”. IPGM which is used for grinding aspheric lens increases both the production and grinding performance, and significantly decreases total production costs. To enhance the precision grinding productivity of ultra-precision aspheric lens, we present here an ultra-precision grinding system and process for the aspheric micro-lens. The tool path was calculated and CNC program generation and tool path compensation were performed for aspheric lens. Using this ultra-precision grinding system, aspheric lens, 4mm in diameter, were successfully performed. The profile error after the first grinding without any compensation was less than 0.6μm, and surface roughness Ra was 0.01μm. In-process grinding was performed with compensation. Results of the profile accuracy P-V 0.3μm and surface roughness Ra 0.006 μm were obtained.