Large-Area Film Structure Consisted by Aggregation of Zinc Oxide Micro-Whiskers
- PDF / 105,804 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 107 Downloads / 160 Views
W18.1.1
Large-Area Film Structure Consisted by Aggregation of Zinc Oxide Micro-Whiskers Shuji Tokita, Shigeo Ohshi 1and Hidetoshi Saitoh1 TOKITA CVD Systems Co. Hinode-cho, Yoshida, Nishikannbara-gun, Niigata, 959-0231, JAPAN 1 Nagaoka Univ. Tech. Dept. of Chemistry Kamitomioka, Nagaoka, Niigata, 940-2188, JAPAN
ABSTRACT We developed a chemical-vapor deposition (CVD) apparatus with a 0.5×240 mm2 slit-type This apparatus forms uniform nozzle that scans at an area of 240×315 mm2 in the atmosphere. oxide crystals on substrates through the decomposition process of precursors emitted from the nozzle. In this study, ZnO whiskers were synthesized on a single-crystalline 8-inch wafer of (100)-oriented silicon using this apparatus. Morphological and crystallographic properties of the samples were evaluated using scanning electron microscopy and X-ray diffractometry. INTRODUCTION A chemical-vapor deposition (CVD) technique employed under air atmosphere has several features: (1) no vacuum chamber is needed, (2) metal oxide films are formed and (3) surface morphology and crystalline orientation are designed easily1)-8). The most important feature is an ability to form the ceramic whiskers. The ceramic whiskers possess sharp tips and crowd on the substrate9)-12). The whiskers formed by the CVD technique employed under air atmosphere have been designed to be used in the field of the display technology. For example, aluminum-doped ZnO conductive whiskers (Al:ZnO) were examined as an cold emitter that is one of the important candidates for the electron source of field emission displays (FEDs). Ohkawara et. al. 2 manufactured a 15x15 mm FED using the cold emitter consisted of Al:ZnO whiskers coated with amorphous carbon nitride (a-CNx) film13). In addition, Saitoh et. al. reported that the work function of a-CNx was dependent upon the functional group14). Furthermore, Tokita et. al. designed a 0.5x50 mm2 slit-type nozzle and scanned it on single crystalline substrates of (100) silicon for 7.5 h. The homogeneous Al:ZnO whiskers were grown on the substrate with an area of 50x50 mm2 15). We believe that the large-area deposition technique of the ZnO whiskers supports technological development of the ceramic-whisker FED. We developed a chemical-vapor deposition (CVD) apparatus with a 0.5×240 mm2 slit-type nozzle that scans at an area of 240×315 mm2 in the atmosphere. This apparatus forms uniform oxide crystals on substrates through the decomposition process of precursors emitted from the nozzle. In this study, ZnO whiskers were synthesized on a single-crystalline 8-inch wafer of (100)-oriented silicon using this apparatus. Morphological and crystallographic properties of
W18.1.2
the samples were evaluated using scanning electron microscopy and X-ray diffractometry. EXPERIMENTAL DETAILS The CVD apparatus with two scanning nozzles was employed under air atmosphere, as shown in Fig. 1. The reactant, 20 g of Zn(C5H7O2)2 (Soekawa Chemical Co., quoted purity of 99.9%) was loaded into two vaporizers and vaporized at 122 . The inside tempe
Data Loading...
