Process control method in spin etching and spin etching apparatus

Abstract

The present invention provides a process control method in spin etching capable of realizing uniformity in etching amount in etching treatment for even wafers each having various conditions, and achieving uniformity of thickness values among etched wafers. In the present invention, weight of a wafer before etching is measured in units of 1/1000 g, followed by predetermined etching treatment in a spin etching section. Thereafter, weight of the wafer is again measured in units of 1/1000 g after rinsing and drying treatment of the wafer, and then an actual etching amount is calculated from a difference between weight before and after etching of the wafer, confirming an etching rate each time etching to thereby control an etching time.

1 . A spin etching apparatus comprising: a spin etching section for etching a wafer; an etching solution circulating tank for storing and circulating the etching solution; an etching solution feed line for feeding the etching solution from the etching solution circulating tank to the spin etching section; an etching solution recovering line for recovering the etching solution used in the spin etching section into the etching solution circulating tank; a weight measuring section for measuring weight before and after etching of the wafer etched in the spin etching section; and a handling mechanism section in which the wafer to be etched is transferred to the weight measuring section, and after the weight of the wafer is measured, the wafer is transferred to the spin etching section, the etched wafer is transferred to the weight measuring section from the spin etching section, and after the weight of the etched wafer is measured, the wafer is taken out from the weight measuring section.