| 摘要 |
PURPOSE:To evaluate the depth of an upper side or lower side separation diffusion layer by measuring dielectric resistance between the separation diffusion layer formed to an epitaxial layer on a substrate and the same conduction type thin layer shaped to the epitaxial layer while opposing to the separation diffusion layer. CONSTITUTION:The lower side diffusion layer 3 is formed to the N type epitaxial layer 2 on the P type Si substrate 1. The P type separation diffusion layer 4 is shaped to a section opposing to the diffusion layer 3 on the surface of the epitaxial layer 2. The wafer is placed on a metallic base 5, and the dielectric resistance between the lower side P type separation diffusion layer 3 and the P type diffusion thin layer 4 is measured by means of a curve tracer 6. The depth of the lower side diffusion layer can be evaluated because relationship between a distance between the diffusion layer 3 and the thin layer 4, the width of the epitaxial layer 2, and dielectric resistance is grasped previously and the thickness of the thin layer and the epitaxial layer 2 is also known. Accordingly, the depth of the diffusion layer is easily evaluated and controlled. |
