A monolithic 14 bit D/A converter fabricated with a new trimming technique (DOT)

An electrical trimming technique for a heavily doped polysilicon resistor (DOT) has been successfully applied to the fabrication of a monolithic 14-bit D/A converter. The converter trimmed by DOT showed a nonlinearity error of less than 1/4 LSB, which means the converter substantially has 15-bit accuracy. Resistance post-trimming stability is greatly improved by introducing an excess trimming and restoration process in DOT, resulting in the achievement of a resistance stability of within /spl plusmn/0.01% of 100 years use at 100/spl deg/C.