MANUFACTURE OF SEMICONDUCTOR DEVICE

• Main Authors: INABA KEIZO, TATEFURU NOBORU
• Format: Patent
• Language: English
• Published: 05.03.1993
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To control electric characteristics of a semiconductor dence after electrodes of the element are formed by finely controlling the width of a base by changing the extent of an impurity diffused layer by heating a wafer while or after irradiating up to the vicinity of the junction of an emitter and the base with an electromagnetic wave after the electrodes are formed. CONSTITUTION:An impurity diffused region such as a base region 2, an emitter region 3, etc., is formed on one main surface of a semiconductor substrate 1, and electrodes 8 made of Al, etc., are formed thereon. Thereafter, the substrate 1 is irradiated with electromagnetic waves 9 such as gamma-ray, etc. The irradiating intensity, the irradiating time of the wave at this time are controlled to values necessary to obtain designed value of hFE characteristics of a semiconductor device. It is heat treated at a temperature at which the Al electrodes are not damaged while or after irradiating it with the wave. Thus, impurity atoms in a semiconductor crystalline structure become easily movable, and diffusion of the impurity is accelerated. Accordingly, the width of the base is varied, and fine control of the hFE value is performed even after the formation of the electrodes.