FABRICATION OF SUBMICRON CONTACT HOLE WITH A FOCUSED ION-BEAM

In order to obtain reproducibility for fabricating microcontact holes in insulator film on the semiconductor substrate, a method of controlling focused ion beam irradiation by monitoring the absorption current was examined. The holes which penetrated the insulator (SiO2) film and just reached the surface of the semiconductor (Ge) substrate were fabricated by stopping the irradiation of the ion beam just after the absorption current of the sample passed through its maximum value. Using this method, holes with a contact area of the order of 10-10 cm2 were obtained with good reproducibility. © 1990 The Japan Society of Applied Physics.