DIFFUSION FURNACE DEVICE AND DIFFUSION METHOD

PROBLEM TO BE SOLVED: To prevent a diffusion furnace from being contaminated by keeping an in-furnace temperature distribution constant by preventing a heating gas from flowing to the outside of a furnace core tube becoming a problem when a substrate is taken in and out, and further suppressing inflow of outside air into the furnace core tube. SOLUTION: The diffusion furnace device including the furnace core tube 11 for thermally diffusing a dopant into the substrate 17, and a mother boat 15 configured to enter and exit from the furnace tube through a substrate entrance exit of the furnace tube while mounted with the substrate is provided with a cap body, having a notch that the mother boat mounted with the substrate enters and exits from, at the substrate entrance exit, and also provided with a screen body for closing the substrate entrance exit at a rear of the mother boat, thereby preventing the outside air from flowing in the furnace core tube and also preventing the heating gas from flowing out of the furnace core tube when the mother boat mounted with the substrate is taken in and out of the furnace core tube through the substrate entrance exit. COPYRIGHT: (C)2010,JPO&INPIT