| 摘要 |
PURPOSE:To improve yield on the manufacture of mesa type devices by executing a step in which an opening is formed at the top section of a mesa to an insulating film for constricting currents in a self-alignment manner. CONSTITUTION:Mesa etching is conducted by using a mask consisting of multilayer films 6, 7, 8, and a insulaing film for constricting currents is applied onto the whole surface of a substrate under the state in which the mask is left. A material is selected previously so that the chemical etching rate of the insulating film is made sufficiently smaller than the etching rate of any film in the multilayer films at that time. When chemical etching is performed under the state, an etchant starts intrusion from the incomplete position of the coating of the insulating film in an undercut section in the multilayer films employed as the mask, and lastly a dielectric layer 7 as a second layer can be removed perfectly while a dielectric layer 6 as a first layer is also got rid of, thus exposing only the top section of a mesa. The insulating film for constricting currents is not taken off because it is difficult to etch at that time. Consequently, an opening can be bored in a self-align-ment manner at the top section of the mesa to the insulating film 11 for constricting currents. Accordingly, the lowering of yield on manufacture due to the positional displacement of the opening can be avoided.
|
