Forming method of silicide film
View Patent ↗A manufacturing method of a semiconductor device includes forming a cobalt film on a silicon substrate on which a diffusion layer is formed, forming a titanium film on the cobalt film using a titanium target having a surface from which a nitride film has previously been removed, forming a titanium nitride film containing titanium on the cobalt film by a reactive sputtering process using a nitrogen gas and the titanium target, and performing an annealing to react the cobalt film with the silicon substrate, thereby accomplishing silicification.
1. A forming method of a silicide film comprising:
forming a cobalt film on a silicon substrate on which a diffusion layer is formed;
forming a titanium film on the cobalt film by sputtering a titanium target;
forming a titanium nitride film on the titanium film by sputtering the titanium target in a nitrogen gas atmosphere so that the titanium target is nitrided;
cleaning the nitrided titanium target; and
after said cleaning, performing a heat treatment to react said cobalt film with said silicon substrate, thereby forming a cobalt silicide film.
2. The forming method of the silicide film according to claim 1 , wherein said titanium nitride is formed by a reactive sputtering process.
3. A method of manufacturing a silicide film comprising:
preparing a silicon substrate having a surface thereof;
forming a diffusion layer on the surface of the silicon substrate;
forming a cobalt layer on the surface of the silicon substrate including the diffusion layer;
forming a titanium film on the cobalt layer by a sputtering method using a titanium target;
forming a titanium nitride layer on the titanium film by a sputtering method using the titanium target in a nitrogen atmosphere, so that a titanium nitride layer is formed on a surface of the titanium target;
removing the titanium nitride layer formed on the titanium target; and
after said removing, reacting the cobalt layer with the silicon substrate by a heat treatment so as to form a cobalt silicide layer.
4. A method of manufacturing a silicide film according to claim 3 , wherein said forming a cobalt layer, said forming a titanium film and said forming a titanium nitride layer are conducted within a multi-chamber equipment.
5. A method of manufacturing a silicide film according to claim 4 , wherein said forming a cobalt layer, said forming a titanium film and said forming a titanium nitride layer include:
setting the silicon substrate into the multi-chamber equipment;
degassing the multi-chamber equipment;
sputtering cobalt onto the surface of the silicon substrate to form the cobalt layer;
sputtering titanium on the cobalt layer to form the titanium film; and
sputtering titanium in the nitrogen atmosphere onto the titanium film so that the titanium nitride layer is formed on the titanium film.
6. A method of manufacturing a silicide film according to claim 3 , wherein said removing includes:
ceasing a supply of nitrogen and supplying an argon gas; and
sputtering titanium into the argon atmosphere so as to form a titanium layer on the titanium nitride layer and to clean a surface of the titanium target.
7. A method of manufacturing a suicide film according to claim 3 , wherein said reacting includes:
subjecting the silicon substrate to a first rapid thermal annealing so as to change the cobalt layer on the diffusion layer into a cobalt monosilicide layer;
removing unchanged portions of the cobalt layer, the titanium film and the titanium nitride layer; and
subjecting the silicon substrate to a second rapid thermal annealing so as to change the cobalt monosilicide layer into a cobalt disilicide layer.
8. A method of manufacturing a silicide film according to claim 7 , wherein the first rapid thermal annealing is conducted at about 550° C. for about 30 seconds within a nitrogen atmosphere.
9. A method of manufacturing a silicide film according to claim 7 , wherein the second thermal annealing is conducted at about 850° C. for about 30 seconds within a nitrogen atmosphere.