TAILORED ANAYSES FOR MULTI-PERIOD LOW-EMISSIVITY FILTER DEPOSITED BY RF MAGNETRON SPUTTERING

초록

It is known that the multiple repetition of a basic low-emissivity(low-e) coating with a noble metal film can be used for display applications. In this study we designed and fabricated multi-period low-e filters based on the basic structure of [TiO2|Ti|Ag|TiO2], using a RF magnetron sputtering. Thickness of Ti thin film should be determined so as to block the diffusion of Ag into TiO2 film in the sputtering process as well as to absorb the visible light as small as possible. To study the role of Ti blocking layer of 1~2 nm thickness, the optical performance of low-e filter was examined by measurement of transmittance and reflectance with a spectrophotometer. The structrual, chemical, and electrical properties were investigated by use of SEM, AES, RBS, and a four-point probe. The results show that ~1nm of Ti blockers in the three periods of the basic structure was not enough to completely protect the Ag layers from contamination, the average thransmittance of the low-e filter was 61.1% in the visible, and the sheet resistance was 0.9Ω/sq. On the other hand, ~2 nm Ti blockers resulted in complete protection of the Ag layers, the average transmittance was decreased to 53.4%, and the sheet resistance was increased to 1.16Ω/sq. Therefore it seems that the optimum thickness for Ti blockers needs a tradeoff among the optical performance, the structrual and chemical stability, and the electrical property. Also we will report the analyses for various low-e filter structures.