VERTICAL DIFFUSION FURNACE

To provide a vertical diffusion furnace that prevents the generation of wake turbulence of introduction gas behind a diffuser panel, and ensures uniform flow of the introduction gas to a wafer.SOLUTION: A vertical diffusion furnace comprises: a process tube that has a peripheral wall part having a central axis arranged along the vertical direction, an upper wall part connected with the peripheral wall part and provided to cover an upper part of the peripheral wall part, and an introduction part provided on the upper wall part for introducing introduction gas; and a diffusion and rectification part having a diffusion part that is arranged inside the process tube and below the introduction part, and diffuses the introduction gas blown from an upper part in the radial direction of the process tube and subsequently guides the gas to a lower part, and a rectification part that has a tapered part that is tapered toward the lower part and having a leading end with a downward convex shape, and is provided below a current transformation part that diffuses the introduction gas in the radial direction in the diffusion part. The dimension of the height along the axial direction of the central axis of the rectification part is larger than the maximum dimension of the width of the current transformation part corresponding to a position where the rectification part is provided.SELECTED DRAWING: Figure 2 【課題】本発明は、拡散板の後方で導入ガスの後方乱流が発生することを抑制し、導入ガスのウエハへの均一な流れを確保する縦型拡散炉を提供する。【解決手段】縦型拡散炉は、中心軸が鉛直上下方向に沿って配置される周壁部と、周壁部に接続し、周壁部の上方を覆うように設けられた上壁部と、上壁部に設けられた導入ガスを導入する導入部と、を有するプロセスチューブと、プロセスチューブの内部において導入部の下方に配置され、上方から吹き付けられる導入ガスを、プロセスチューブの径方向に拡散させた後、下方に導く拡散部と、下方に進むにつれて先細り、先端部が下方に凸状である先細部を有し、拡散部において導入ガスを径方向に拡散させる変流部の下方に設けられた整流部と、を有する拡散整流部と、を備える。整流部の中心軸の軸方向に沿う高さの寸法は、整流部が設けられた位置に対応する変流部の幅の最大寸法と比較して、大きい。【選択図】図２