High heat resistance resist composition and pattern forming method using the same

1. A negative pattern formation method comprising the steps of coating a substrate with a chemically amplified negative-type resist composition comprising

(I) a polymer containing the repeating unit represented by the following formula (Ia):

in which

A is hydrogen or a hydrocarbon group having 1 to 3 carbon atoms,

B is a hydrocarbon group having 1 to 5 carbon atoms, and

x is an integer of 0 or more,

y is an integer of 1 or more,

under the conditions of x+y≤5;

(II) a crosslinking agent represented by the following formula (IIa)

in which

n is an integer of 1 or more,

R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 15 carbon atoms, and

R2 is hydrogen, hydroxyl or a substituted or unsubstituted hydrocarbon group having 1 to 15 carbon atoms;

wherein at least one of said R 1 and R2 is a naphthyl group;

(III) an acid generating agent; and

(IV) a solvent, to form a composition layer;

(1) pre-baking said composition layer;

(2) exposing to light the substrate coated with the composition layer after said pre-baking step;

(3) carrying out post exposure baking after said exposure step; and

carrying out development with an alkali aqueous solution after said post exposure baking step.

2. The negative pattern formation method according to claim 1 , wherein said polymer is represented by the following formula (Ib)

in which

x and y are numbers indicating the polymerization ratios provided that x is not equal to 0, the repeating units of each side may be polymerized either randomly or to form blocks,

each of G and H is independently hydrogen or a hydrocarbon group having 1 to 3 carbon atoms,

each of I and J is independently a hydrocarbon group having 1 to 5 carbon atoms, and t, an integer of 0 or more

u an integer of 1 or more and

v an integer of 0 to 5, under the condition of t+u<5.

3. The negative pattern formation method according to claim 2 , wherein said polymer represented by the above formula (Ib) has a polymerization ratio x:y in the range of 87:13 to 100:0.

4. The negative pattern formation method according to claim 2 , wherein said polymer represented by the above formula (Ib) has a polymerization ratio x:y in the range of 30:70 to 100:0.

5. The negative pattern formation method according to claim 2 , wherein the polymerization ratio y is 0 in said polymer represented by the above formula (Ib).

6. The negative pattern formation method according to claim 1 , wherein the content of said crosslinking agent is in the range of 5 to 30 weight parts based on 100 weight parts of said polymer (I).

7. The negative pattern formation method according to claim 1 , wherein said n is an integer of 1 to 3 inclusive.

8. The negative pattern formation method according to claim 1 , wherein said crosslinking agent represented by the formula (IIa) has a weight average molecular weight of 300 to 2000.

9. The negative pattern formation method according to claim 1 , wherein said crosslinking agent has a glass transition temperature in the range of 150 to 250° C.

10. A negative pattern formation method comprising the steps of coating a substrate with a chemically amplified negative-type resist composition comprising

(I) a polymer containing the repeating unit represented by the following formula (Ia):

in which

A is hydrogen or a hydrocarbon group having 1 to 3 carbon atoms,

B is a hydrocarbon group having 1 to 5 carbon atoms, and

x is an integer of 0 or more,

y is an integer of 1 or more,

under the conditions of x+y<5;

(II) a crosslinking agent represented by the following formula (IIa)

(IIa′)

in which

n is an integer of 1 to 3 or has an average molecular weight of 500 to 800,

(Ill) an acid generating agent; and

(IV) a solvent, to form a composition layer;

(4) pre-baking said composition layer;

(5) exposing to light the substrate coated with the composition layer after said pre-baking step;

(6) carrying out post exposure baking after said exposure step; and

carrying out development with an alkali aqueous solution after said post exposure baking step.

11. The negative pattern formation method according to claim 10 , wherein said polymer represented by the above formula (Ib) has a polymerization ratio x:y in the range of 30:70 to 100:0.

12. The negative pattern formation method according to claim 10 , wherein the content of said crosslinking agent is in the range of 5 to 30 weight parts based on 100 weight parts of said polymer (Ia).

13. The negative pattern formation method according to claim 10 , wherein said crosslinking agent represented by the formula (Ila) has a weight average molecular weight of 300 to 2000.

14. The negative pattern formation method according to claim 10 , wherein said crosslinking agent has a glass transition temperature in the range of 150 to 250° C.