| 摘要 |
PROBLEM TO BE SOLVED: To selectively diffuse aluminum in a predetermined concentration in one side surface of a silicon substrate even in the case of an open tube type by coating a surface of the substrate of the state that a surface residual strain layer by machining is retained with an aluminum compound solution, and heat- treating it in a mixed gas atmosphere of argon gas and oxygen gas. SOLUTION: A coated aluminum dissolved solution is immersed into a residual strain layer by machining of a semiconductor silicon substrate machined by free abrasive grains or stationary abrasive grains. Drying of the surface is waited, the substrates are disposed at a predetermined interval in a process tube, a mixed gas of argon and oxygen is introduced into the tube, and the substrates are heat-treated at an atmospheric pressure in a mixed gas atmosphere. At this time, oxide films are formed on the surfaces of the substrates by a reaction of oxygen in the mixed gas. This is operated to prevent an outer diffusion of the aluminum sufficiently implanted in the form of already immersing the solution to the strain layer in the surface of the substrate.
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