| 摘要 |
PURPOSE:To eliminate variations by a treatment condition by monitoring the cumulative value of current flowing into a semiconductor wafer and by controlling the thickness of an oxide film when positive oxidation is made for the semiconductor wafer. CONSTITUTION:Oxidation is made by attracting the semiconductor wafer 2a to a positive electrode 1a and by equally spraying a forming solution 3a to the semiconductor wafer 2a from a spray tank 4b providing a spray head 6a by fixing a negative plate 5a in the tank. At that time, a current value is measured by a detection section 3b every scanning interval time. And the product of the current value and the scanning interval time is totalled by a charge volume calculating section 4b. The total value and the value obtained from the charge volume setting section 6b are collated 5b and judgement is done by a stop control section 7b. And when stoppage is necessary, formation will be suspended by turning off a regulated power supply 1b. In this way, variations in film thickness will be eliminated in spite of the conditions such as contact status of the semiconductor wafer and the positive electrode and that of the forming solution and the semiconductor wafer. |
