Semiconductor device and manufacturing method thereof
View Patent ↗An element larger than silicon is ion-implanted to a contact liner in an N-channel region to break constituent atoms of the contact liner in the N-channel region. An element larger than silicon is ion-implanted to the contact liner in a P-channel region to break constituent atoms of the contact liner, oxygen or the like is ion-implanted. Thereafter, heat treatment is performed to cause shrinkage of the contact liner in the N-channel region to form an n-channel contact liner, and to cause expansion of the contact liner in the P-channel region to form a p-channel contact liner.
1. A semiconductor device, comprising:
a semiconductor substrate;
an element isolation region for electrically isolating a first active region in an N-channel region from a second active region in a P-channel region in the semiconductor substrate;
an n-channel field effect transistor having an n-channel gate formed on the first active region with a gate insulating film interposed therebetween and a first source/drain region formed on both sides of the n-channel gate in the first active region;
a p-channel field effect transistor having a p-channel gate formed on the second active region with a gate insulating film interposed therebetween and a second source/drain region formed on both sides of the p-channel gate in the second active region;
an n-channel contact liner formed over the first active region and side surfaces and a top surface of the n-channel gate and having a shrinkage force;
a p-channel contact liner formed over the second active region and side surfaces and a top surface of the p-channel gate, formed continuously with the n-channel contact liner so as to have a larger thickness than that of the n-channel contact liner, and having an expansion force; and
a contact liner formed between the first active region and n-channel field effect transistor and the n-channel contact liner and between the second active region and p-channel field effect transistor and the p-channel contact liner, wherein:
the n-channel contact liner and the p-channel contact liner are made of a same base material and contain different impurity atoms from each other, and
the contact liner is made of the same base material as that of the n-channel contact liner and the p-channel contact liner and has a smaller density of the impurity atoms than that of the impurity atoms in the n-channel contact liner and the p-channel contact liner.
2. The semiconductor device according to claim 1 , wherein the base material of the n-channel contact liner and the p-channel contact liner is silicon nitride and a density of Si—N bonds in the n-channel contact liner is higher than that of Si—N bonds in the p-channel contact liner.
3. The semiconductor device according to claim 1 , wherein the n-channel contact liner contains carbon or fluorine as the impurity atoms.
4. The semiconductor device according to claim 1 , wherein the p-channel contact liner contains oxygen as the impurity atoms.
5. The semiconductor device according to claim 1 , wherein the n-channel contact liner and the p-channel contact liner contain an element having an ionic radius equal to or larger than that of silicon at a higher concentration than that in the contact liner.
6. The semiconductor device according to claim 5 , wherein the n-channel contact liner and the p-channel contact liner contain silicon, arsenic, indium, or germanium at a higher concentration than that in the contact liner.
7. The semiconductor device according to claim 1 , wherein the p-channel contact liner contains Ge at a higher density than that in the n-channel contact liner.
8. The semiconductor device according to claim 1 , wherein a density of Si—H bonds in the n-channel contact liner and the p-channel contact liner is higher than that of Si—H bonds in the contact liner.
9. The semiconductor device according to claim 1 , wherein a difference in level between the n-channel contact liner and the p-channel contact liner in a boundary region between the N-channel region and the P-channel region is 3 nm to 15 nm.
10. A semiconductor device, comprising:
a semiconductor substrate;
an element isolation region for electrically isolating a first active region in an N-channel region from a second active region in a P-channel region in the semiconductor substrate;
an n-channel field effect transistor having an n-channel gate formed on the first active region with a gate insulating film interposed therebetween and a first source/drain region formed on both sides of the n-channel gate in the first active region;
a p-channel field effect transistor having a p-channel gate formed on the second active region with a gate insulating film interposed therebetween and a second source/drain region formed on both sides of the p-channel gate in the second active region;
an n-channel contact liner formed over the first active region and side surfaces and a top surface of the n-channel gate and having a shrinkage force;
a p-channel contact liner formed over the second active region and side surfaces and a top surface of the p-channel gate-and having an expansion force; and
a boundary region formed between the n-channel contact liner and the p-channel contact liner, wherein
the p-channel contact liner has a larger thickness than that of the n-channel contact liner, and
the n-channel contact liner, the p-channel contact liner and the boundary region are formed continuously.
11. The semiconductor device according to claim 10 , wherein the n-channel contact liner and the p-channel contact liner are made of a same base material and contain different impurity atoms from each other.
12. The semiconductor device according to claim 11 , further comprising a contact liner formed between the first active region and n-channel field effect transistor and the n-channel contact liner and between the second active region and p-channel field effect transistor and the p-channel contact liner, wherein the contact liner is made of the same base material as that of the n-channel contact liner and the p-channel contact liner and has a smaller density of the impurity atoms than that of the impurity atoms in the n-channel contact liner and the p-channel contact liner.
13. The semiconductor device according to claim 12 , wherein the n-channel contact liner and the p-channel contact liner contain an element having an ionic radius equal to or larger than that of silicon at a higher concentration than that in the contact liner.
14. The semiconductor device according to claim 13 , wherein the n-channel contact liner and the p-channel contact liner contain silicon, arsenic, indium, or germanium at a higher concentration than that in the contact liner.
15. The semiconductor device according to claim 12 , wherein a density of Si—H bonds in the n-channel contact liner and the p-channel contact liner is higher than that of Si—H bonds in the contact liner.
16. The semiconductor device according to claim 10 , wherein a base material of the n-channel contact liner and the p-channel contact liner is silicon nitride and a density of Si—N bonds in the n-channel contact liner is higher than that of Si—N bonds in the p-channel contact liner.
17. The semiconductor device according to claim 10 , wherein the n-channel contact liner contains carbon or fluorine as impurity atoms.
18. The semiconductor device according to claim 10 , wherein the p-channel contact liner contains oxygen as impurity atoms.
19. The semiconductor device according to claim 10 , wherein the p-channel contact liner contains Ge at a higher density than that in the n-channel contact liner.
20. The semiconductor device according to claim 10 , wherein a difference in level between the n-channel contact liner and the p-channel contact liner in a boundary region between the N-channel region and the P-channel region is 3 nm to 15 nm.