Integrated circuit with a metal silicide film uniformly formed

A method of manufacturing an integrated circuit comprising the steps of manufacturing an integrated circuit assembly having an exposed assembly surface and including a semiconductor substrate and a doped silicon part formed of p-type and n-type diffusion regions along said semiconductor substrate to consist essentially of silicon and to have an exposed part surface as a portion of assembly surface;

• forming a metal film on said exposed assembly surface to provide an integrated circuit composite;
• and heat treating said integrated circuit composite so as to turn said metal film into a metal silicide film having a uniform thickness on both said p-type and n-type diffusion regions of said exposed part surface, wherein said heat treating step is carried out first at a primary temperature between 600.degree. C. and 700.degree. C. and subsequently at a secondary temperature between 700.degree. C. and 900.degree. C., said heat treating step comprising first and second heat treating steps, both carried out in a nitrogen atmosphere consisting essentially of nitrogen, wherein:
• wherein said integrated circuit assembly includes a silicon dioxide portion formed on said semiconductor substrate to consist essentially of silicon dioxide and to have an exposed portion surface as a part of said exposed assembly surface;
• said first heat treating step comprises first primary and secondary heat treating steps, said first primary heat treating step using said primary temperature as a first primary temperature, said first secondary heat treating step using said secondary temperature as a first secondary temperature;
• said second heat treating step is carried out at a second temperature between 700.degree. C. and 900.degree. C.;
• and
• the method further comprising the step of removing a metal nitride film after said first secondary heat treating step and before said second heat treating step.

A method of manufacturing an integrated circuit, comprising the steps of:

• forming a doped silicon part as p-type and n-type diffusion regions along a semiconductor substrate and a polysilicon part as a gate electrode between each set of said p-type diffusion regions and said n-type diffusion regions to provide a silicon part having an exposed part surface as a portion of an exposed assembly surface;
• forming a metal film on said exposed assembly surface to provide an integrated circuit composite;
• and
• heat treating said integrated circuit composite to turn said metal film into a metal silicide film on said exposed part surface, wherein:
• said method further comprises the step of carrying out ion injection of ions of a single impurity simultaneously into said p-type and said n-type diffusion regions and said gate electrode to turn said silicon part into an amorphous silicon part adjacent to said exposed part surface;
• said heat treating step comprising first and second heat treating steps, both carried out in a nitrogen atmosphere consisting essentially of nitrogen, said first heat treating step comprising:
• a first primary heat treating step of turning said metal film into a higher resistivity metal silicide film on said silicon part and into a spurious film on said higher resistivity metal silicide film;
• and
• a first secondary heat treating step, at a higher temperature than said first primary heat treating step, of turning said spurious film into a metal nitride film and of turning in cooperation with said second heat treating step said higher resistivity metal silicide film into a lower resistivity metal silicide film;
• said method still further comprising the step of removing said metal nitride film after said first secondary heat treating step and before said second heat treating step.

A method of manufacturing a complementary metal-oxide-semiconductor integrated circuit, comprising the steps of:

• forming doped silicon part as p-type source and drain regions and n-type source and drain regions along a semiconductor substrate and a polysilicon part as a gate electrode between each set of said p-type source and drain regions and said n-type source and drain regions to provide a silicon part having an exposed part surface as a portion of exposed assembly surface;
• forming a silicon dioxide portion between said gate electrode and each of said p-type and said n-type source and drain regions, and forming a silicon dioxide element isolation portion around each set of said p-type source and drain regions and said n-type source and drain regions to form a collective dioxide portion having an exposed portion surface an another part of said exposed assembly surface;
• forming a metal film on said exposed assembly surface to provide an integrated circuit composite;
• and
• heat treating said integrated circuit composite to turn said metal film into a metal silicide film on said exposed part surface and into a metal oxide film on said portion surface;
• wherein said method further comprises the step of carrying out ion injection of ions of a single impurity simultaneously into said p-type and said n-type source and drain regions and said gate electrode to turn said silicon part into an amorphous silicon part adjacent to said exposed part surface;
• said heat treating step comprising first and second heat treating steps, both carried out in a nitrogen atmosphere consisting essentially of nitrogen, said first heat treating step comprising:
• a first primary heat treating step of turning said metal film into a higher resistivity metal film on said exposed part surface, into a metal oxide film on said exposed portion surface, and into a spurious film on said metal silicide and oxide films;
• and
• a first secondary heat treating step, at a higher temperature than said first heat treating step, of turning said spurious film into a metal nitride film and of turning in cooperation with said second heat treating step said higher resistivity metal silicide film into a lower resistivity metal silicide film.