| 摘要 |
PROBLEM TO BE SOLVED: To prevent dopant from depositing on the surface of a BPSG film, and exclude crystal defect, by progressing a flow process for flattening, after impurities are diffused outward, in an oxide film containing the dopant, at a specific temperature. SOLUTION: An interlayer insulating film 17 is formed on the upper part of a semiconductor device wafer 10 having step-difference. A BPSG film 18 as a flattening film containing dopant is formed on the interlayer insulating film 17. In order to diffuse the dopant in the BPSG film 18 to the outside, a semiconductor device wafer 10 is loaded in the reaction chamber of an LPCVD equipment, and heat-treated at specific temperature and pressure. Thereby, the surface concentration of the BPSG film 18 is decreased due to external diffusion. In order to make the BPSG film 18 flow, the temperature in the reaction chamber of the LPCVD equipment is increased up to 850-900 deg.C, and heat treatment is performed in a nitrogen atmosphere. Thereby, the BPSG film 18 is made to flow, the surface of the wafer 10 is flattened, and deposition of the dopant is eliminated. |
