METHOD AND DEVICE FOR END POINT DETECTION

• Main Authors: MAEJIMA HIROSHI, WAKIYAMA FUMITOSHI, SEKIGUCHI KOICHIRO, OKABE TSUTOMU, KAMIOKA TETSUYA, HANAJIMA SHUICHI
• Format: Patent
• Language: English
• Published: 30.04.1987
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To improve the accuracy for detecting an end point of etching by a method wherein, when dry etching is performed on a thin film formed on the surface of a semiconductor wafer to form a prescribed pattern, different wavelengths of emission spectrums emitted from the thin film are combined and the peak position of this differential waveform is regarded as the end point of etching. CONSTITUTION:A parallel plate electrode 7 consisting of a lower electrode 5 whereon a semiconductor wafer 4 is placed and an upper electrode 6 is arranged over a substrate part 1 of a plasma etching device having an exhaust tube 9 and this electrode 7 is covered with a bell-jar 2 made of transparent quartz. Moreover, the electrode 5 is earthed, the electrode 6 is connected to an external high-frequency power source 8 and gas is fed in a treating chamber 3 in the interior of the bell-jar 2 from a reaction gas control mechanism 10 through a supply pipe 11. Thereafter, the gas is activated with plasma 12 generated, lights emitted from a thin film formed on the semiconductor wafer surface are processed in a combination circuit part 17 through BPFs 14a and 14b, photo diodes 13a and 13b, amplifying parts 15a and 15b and A/D converters 16a and 16b outside the bell-jar 2. Then, a differential calculation is executed in a decision part 18 and the power source 8 is stopped using the peak of the waveform.