JPS55133557A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the soft error of a semiconductor memory by disposing a semiconductor chip active region in a package nearer to the cap side from the plane of a sealed glass layer to largely reduce alpha ray dosage incident to the active region. CONSTITUTION:Insulating base and cap 1 mand 8 made of high alumina formation ceramic for forming a package are prepared. An alpha ray shield 7 made of high purity material plate is secured into the central recess of a cap 8. An intermediate plate 4 having low thermal expansion coefficient is disposed at the central recess of the base 1, and a silicon chip 5 is secured onto the plate 4. The cap 8 is then secured to the base 1, and a package is airtightly sealed. Since the plate 4 is interposed to approach the active region 5A of a semiconductor chip 5 nearer to the cap side from the plane of the sealed glass layers 2a, 2c, it can prevent the erroneous operation of a semiconductor memory owing to alpha rays irradiated from the sealing glasses 2a, 2c.