| 摘要 |
PURPOSE:To provide a titled device which performs automatically and surely etching to a desired thickness by detecting the actual progressing condition of etching under the actual conditions under which the various conditions for determining the progressing state of the etching are overlapped and setting the time for etching. CONSTITUTION:A body to be etched such as a semiconductor wafer or the like is immersed in an etching liquid 1 in a liquid tank 3 and the liquid temp. in said stage is detected 5. The liquid temp. introduced into a control part 9 for data collection is stored for the read-in time set in an arithmetic part 10, for example, 60sec and 120sec after the point of the time when the etching is started and the change rate (k) of the temp. is calculated. More specifically, a gradient (k) is calculated in the part 10 from the change in the liquid temp. T with respect to the lapse time (t) from the point of the time when the etching is started, i.e., the difference between the liquid temp. T1 in 60sec and the difference in the liquid temp. T2 in 120sec. On the other hand, the data of the relation between the change rate (k) of the liquid 1 at the body to be etched and the reaction rate (k) is empirically determined and is preliminarily programmed in the part 10. The data on the change rate (k) and the etching speed gamma are compared in the control part 9 and the time for obtaining the desired etching thickness is calculated. |
