| 摘要 |
<p>PURPOSE:To improve the uniformity of electric characteristics by making an insulating layer contain, as its material components, the material component of a cathode electrode and an insulating impurity component which converts this material component into an insulating material. CONSTITUTION:Si3N4 films are piled up at the position where the cathode electrode is formed of an n-type Si single crystal substrate 1 to form a diffusional mask in a shape of truncated cone with a diameter of 5000Angstrom by photoetching. Next, oxygen is diffused in a portion without the mask 6 by the thermal oxidation method to form an SiO2 insulating layer 3, and the portion of Si remains because oxygen does not invade into the lower portion of the mask 6, so that the portion becomes a cathode electrode 2; when steam oxidation is made, the portion of the electrode 2 conically projects. Then, a gate electrode layer 4' of Mo is formed on the insulating layer 3 by the sputtering technique and the mask 6 is removed by the dry etching method, etc., to make a gate electrode opening 4a. Moreover, the insulating layer 3 is opened to expose a cathode electrode with an HF buffer liquid. As a result, the shortest distance between the cathode electrode 2 and the gate electrode 4 is approximately 2700Angstrom and also their mutual dispersion is lessened.</p> |
