| 摘要 |
PURPOSE:To obtain uniform grown films on semiconductor wafers in an inner tube expanded in diameter in a reaction gas flowing direction and having a plurality of openings by setting the inner tube in an outer tube to make the concn. of reaction gas uniform in the flowing direction. CONSTITUTION:Reaction gas G is introduced into outer tube 1 and let to flow into inner tube 2 mounting wafers 3 through openings 2a of tube 2. The cross-sectional area of the space between tubes 1, 2 in the diametrical direction is gradually reducing from the gas inlet side toward the gas outlet side. Accordingly, gas G introduced into tube 2 flows through a layer which is different in distance from the central axis along the gas flowing direction, and the flow rate is raised slowly. As a result, by holding the press. of gas G present between tubes 1, 2 about constant and making the concn. of gas G introduced into tube 2 constant, uniform grown films are obtd. on wafers 3. |
