| 摘要 |
PURPOSE:To accomplish properly selected etching of the insulator film on the semiconductor wafer by heating the wafer within a quartz capsule sealed in the etchant atmosphere. CONSTITUTION:An appropriate liquid of H2O and HF prepared at a ratio of 10 to 1 as etchant is sealed into a quarts capsule with an Si substrate coated with an SiO2 film, Si3N4 film and PSG film and maintained at 150 deg.C, and then undergoes an etching under the internal pressure of about 10kg/cm<2>. Thereupon, utterly contrary to the usual chemical etching, the Si3N4 film and the PSG film are etched but the Si substrate and the SiO2 film won't be done at all. Depending on the selection of the etchant material and the pressure within the capsule, the etching ratio vaied with the difference in the material can be increased noticeably more than that of the conventional dry etching. Therefore, properly selcted etching is possible for the insulator film on the semiconductor substrate. The etchant can be of a liquid and gaseous phase. |
