JPH0573273B

PURPOSE:To obtain the largest capacitance value with the least area by forming an MIM capacitance of an insulating film that grows on a gallium arsenide substrate and makes stepped parts after removing unnecessary sections and also forming it on recessed parts prepared on the gallium arsenide substrate after conducting an anisotropy etching treatment by using above insulating film as a mask. CONSTITUTION:A stepped part is prepared by removing unnecessary sections of an insulating film 1 that grows on a gallium arsenide substrate 2 and a V-shaped recessed part is prepared by conducting an anisotropy wet etching treatment with the above film as a mask. The formation of an MIM capacitance on the above insulating film and the recessed areas enables this device to have areas of electrodes 3 and 5 facing each other that are larger than those of conventional MIM capacitance. Accordingly, the largest capacitance can be obtained with the least area.