Patent ID: 6391145
Filing Date: 2002-05-21
Classification: H01L,Y02E,Y02P

Abstract:
An apparatus for producing a semiconductor which comprises an etching device in which a silicon substrate is dipped in an etching liquid composed of an aqueous solution of mixed acid of hydrofluoric acid, nitric acid and an adjusting agent containing phosphoric acid or a water-soluble carboxylic acid having a carbon atom number of 3 to 6, and a detecting means for detecting a concentration of the nitric acid in the aqueous solution of mixed acid,which further comprises a substrate holder for holding the silicon substrate in an upright direction when the silicon substrate is etched in the etching device, wherein the substrate holder is adapted to hold a plurality of silicon substrates in an upright direction with the near surfaces of the silicon substrates in mutual contact when the silicon substrate is etched in the etching device.