A STUDY ON REACTION MECHANISM CONTROL UNDER LIGHT IRRADIATION IN ULTRACLEAN CLEANING OR HEATING PROCESSES OF SILICON SURFACES

超薄二氧化硅薄膜已形成在硅晶片上的超纯氧气体加热与红外光照射，并已被证明是依赖于硅晶片清洗时间与超纯水在兆声波照射下的热氧化前，通过的隧道电流的二氧化硅薄膜或介电击穿电压。超纯水冲洗和超声波辐照10 min是制备高介电性能的SiO2薄膜的最佳工艺。硅基二氧化硅薄膜的介电特性对上升过程所决定的硅片表面的微观粗糙度很敏感。将其上通过热氧化形成了氧化硅膜的硅晶片暴露于空气中，并且已经识别出吸附在二氧化硅表面上的有机物种。已经确定了通过臭氧化超纯水冲洗硅晶片而去除的有机物种或未被有效去除的有机物种。已经发现，在湿法蚀刻期间，通过照射包括具有比硅晶片上的硅带隙的能量高的能量的光的紫外光，蚀刻速率变低，并且蚀刻表面变平坦。已经发现，通过将具有高于硅带隙的能量的半导体激光照射在浸入超纯水中的氢封端的硅晶片上，可以形成二氧化硅膜。这表明硅表面可以通过蚀刻二氧化硅膜来图案化。

Ultrathin silicon dioxide films have been formed on silicon wafers in ultrapure oxygen gas by the heating with infrared light irradiation, and tunneling current through the ultrathin silicon dioxide films or the dielectric breakdown voltage has been demonstrated to depend on the silicon wafer rinsing time with ultrapure water under megasonic irradiation before thermal oxidation. Ultrapure water rinsing with megasonic irradiation for 10 min is optimal to form ultrathin silicon dioxide films with high dielectric performances. The dielectric characteristics of ultrathin silicon dioxide films are sensitive to the microroughness of the silicon wafer surface determined by the rising process. The silicon wafer on which the ultrathin silicon dioxide film is formed by thermal oxidation has been exposed to air, and organic species adsorbed on the silicon dioxide surface have been identified. The organic species removed by ozonized ultrapure water rinsing of the silicon wafer or the organic species which are not efficiently removed have been determined. It has been found that the etching rate becomes low and the etched surface becomes flat by the irradiation of the ultraviolet light including the light with the energy higher than that of the silicon bandgap on a silicon wafer during wet etching. A silicon dioxide film has been found to be formed by the irradiation of the semiconductor laser light with the energy higher than that of the silicon bandgap on a hydrogen-terminated silicon wafer dipped in ultrapure water. This suggests that the silicon surface can be patterned by etching the silicon dioxide film.