Abstract: An MOS transistor with a trench channel and self-aligned source and drain contacts to the interconnection layer. The MOS transistor is fabricated by first etching the substrate of monocrystalline silicon so as to form a trench channel and thereafter filling the trench channel with an anisotropic etched first polycrystalline silicon film. Buried contacts of polycrystalline silicon to the substrate, and Al-Si metallization are used. The trench structure in the channel regions permits the self-alignment of the gate element and the buried contacts to source and drain regions. The MOS transistors of the invention significantly reduce the short channel effect as observed in conventional MOS transistors.

Abstract: An improved polycrystalline silicon resistor having limited lateral diffusion, integrated circuits containing such resistors, and a method of their preparation is disclosed. The polysilicon resistor is formed by first doping the polysilicon layer with a p or n type impurity and thereafter neutralizing the treated layer with impurities of the other type so as to form a device wherein the concentration gradient between the resistor region of the aforesaid layer and its environment is low. The low concentration gradient reduces lateral diffusion during manufacture, thereby permitting manufacture of integrated circuits of higher circuit density and resistors with smaller dimensions, lower temperature coefficients and higher reliability.

Abstract: An improved polycrystalline silicon resistor having limited lateral diffusion, integrated circuits containing such resistors, and a method of their preparation is disclosed. The polysilicon resistor is formed by first doping the polysilicon layer with a p or n type impurity and thereafter neutralizing the treated layer with impurities of the other type so as to form a device wherein the concentration gradient between the resistor region of the aforesaid layer and its environment is low. The low concentration gradient reduces lateral diffusion during manufacture, thereby permitting manufacture of integrated circuits of higher circuit density and resistors with smaller dimensions, lower temperature coefficients and higher reliability.