摘要 |
The invention provides a method for manufacturing adjacent tubs implanted with dopant material ions in the manufacture of LSI complementary MOS field effect transistor circuits (CMOS circuits), and also provides a method sequence for a CMOS process adapted to tub manufacture. In accordance with the principles of the invention, for the greatest possible spatial separation of the tubs, a p-tub (5) is produced before a n-tub (8) and an undercutting (25) of a nitride layer (4) serving as the implantation mask in the p-tub production is intentionally produced, so that, during a subsequent oxidation, the edge of the oxidation is shifted toward the outside by about 1 to 2 mu m. Further, the penetration depth xjn of the n-tub (8) is set smaller by a factor at least equal to 4 relative to the penetration depth xjp of the p-tub (5), whereby the thickness of the n-doped epitaxial layer (2) and the penetration depth xjp are about matched to one another. The two tubs are separately implanted and diffused. As a result of the inventive sequences, the disadvantages of mutual, extensive compensation of the p-tub and the n-tub are avoided.
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