| 摘要 |
PROBLEM TO BE SOLVED: To enable an impurity diffusion layer to be uniformly and continuously formed along the inner wall of a semiconductor substrate, by a method wherein the inner wall of a recess provided to the surface of the semiconductor substrate is subjected to a cleaning treatment, an impurity adsorbtion treatment, and a diffusion treatment. SOLUTION: A trench 42 is provided to the surface of an Si substrate 41, and an inner wall 43 is formed. An insulating film 44 is formed on the surface of the substrate 41 on each side of the trench 42 so as to mask a region where no impurity is injected. An Si oxide film or an Si nitride film is formed through a chemical vapor growth method to serve as the insulating film 44. The inner wall 43 and the exposed surface of the Si substrate 41 are subjected to a cleaning treatment to make active surfaces exposed, and diborane gas is fed to the active surfaces to selectively form an impurity adsorption film 45 which contains boron. The Si substrate 41 is heated to uniformly diffuse impurities boron contained in the adsorption film 45 along the inner wall 43, and an impurity diffusion layer 46 is formed. Then, a pair of electrode films 47 are formed, and thus a trench resistor element is manufactured. |
