Effect of PAG Location on Resists for Next Generation Lithographies

Transcription

1 Effect of PAG Location on Resists for Next Generation Lithographies ber Research Group Materials Science & Engineering Ithaca, NY 14853

2 Development Trends in Microlithography 10 Contact Printer Architectures N X H 3 C N H 3 C Resolution (µm) Cyclized Rubber 436nm 365nm 248nm DNQ - Novolak HS Copolymers 193nm H H H H Hydrocarbon Polymers Year H

3 Positive Chemically Amplified Photoresist Chemistry hv H + H Aqueous Base Dissolution H PAG H 0.40µm ( ) 4 N + H µm

4 Photoacid Generators - PAGs I h? Homolysis I + RS 3 RS 3 XH Radical Abstraction / Protonation X I + RS 3 H Dissociation I H + RS 3

5 Rutherford Backscattering? Depth resolution ~ 200 A Res is t Lay er? RBS spectrum contains information about target s? mass? concentration? depth profile? Most photoacid generators (PAGs) have a self-label such as Sb, I, etc He PAG Ion Beam E (MeV) 0 E 1 E 2 Energy Sensitive Detector E M < M 1 2 E 1 2

6 Diffusion of PAG and Photogenerated Acid Concentration (a.u.) PAG (1) Exposed SbPAG - experimental Exposed SbPAG - simulated Unexposed SbPAG - experimental Unexposed SbPAG - simulated Photogenerated acid (2) Thickness (Â) 120 o C/60s S + Sb F 6 - (1) h?,? H Sb F 6 (2)

7 Photoacid Generator (PAG) Distribution = PAG = Matrix H Br S 2 CF 2 CF 2 CF 2 CF 3 Uneven distribution of PAG Si wafer T-topping Closure Footing

8 Effect of Block Copolymers As Additives THPMA-b-IBMA with and without IBMA-b-MMA additive C C THPMA-b-IBMA with wafer C C MMA-b-IBMA 20 with bcp without bcp Normalized film thickness

9 Block Copolymers as Additives CH 2 CH C 2 CH C 2 C a b c C C C IBM zero thinning resist H 3 C C H MMA-tBMA-MAA with 2 wt% MMA-b-IBMA 5800 A thick films ; PAB -140C/60s PEB - 140C/60s ; Dev TMAH

10 Effect of Block Copolymer Additives - SIMS Measurements 1000 Carbon Photoacid generator Deuterium of Block Copolymer Additive I CF 3 (CF 2 ) 3 S 3 Concentration (a.u.) Iodine of PAG with additive Iodine of PAG without additive (5 wt%) CD 3 CD C b 2 CH 2 C a b C C CD Air-polymer interface Thickness (Å) substrate-polymer interface Block copolymer additive 2 wt%

11 Polymers for Chemically Amplified Photoresists H H + H pk a = 9-10 H + H pk a = 9-10 / pk a = 4-5 H H H + pk a = 4-5 H H H + pk a = 4-5 / Anhydride H

12 Labeling of Photoacid Generators for RBS Self Labeled No Label S S SbF 6 RS 3 CF 3 S 3 I N S 2 CF 3 Heavy Atoms: Sb (51), As (75), Br (79), I (127) Light Atoms: C (12), N (14), (16), F (18), S (32)

13 Design of Labeled PAGs for RBS Study Iodonium Polar PAGs Non Polar Sulfonate Esters I-1 I CF 3 S 3 Br-1 Br S 2 I-2 I CF 3 (CF2) 3 S 3 Br-2 Br S 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 I-3 I CF 3 (CF 2 ) 7 S 3 Br-3 Br S 2 CF 2 CF 2 CF 2 CF 3 H 3 C I-4 I S 3 Br-4 Br S 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 3 I - Labeled Br - Labeled

14 Design of Non-Polar Sulfonate Ester PAGs Moiety to Investigate Structural Effects Br S 2 RBS Label Steric Hindeance for Thermal Stability Thermally Stable in Phenolic and Methacrylate Matrices Photogenerates acid via Blocked Photo-Fries

15 Model Photoresist Matrices 248 nm 193 nm H H H 70/30 57/20/23 Hydrophilic Hydrophobic

16 Distribution of Polar Ionic PAGs in Poly(4-Hydroxystyrene) I CF 3 S 3 I CF 3 (CF2) 3 S 3 Si Air H I CF 3 (CF 2 ) 7 S 3 H 3 C I S 3 S I The distribution of Iodonium PAGs is uniform through the depth of the PHS film independent of counter ion

17 Distribution of Polar Ionic PAGs in 193 nm Acrylic Matrices I CF 3 S I CF 3 (CF2) 3 S CF3S CF3(CF2)3S3 CF3(CF2)7S Normalized film thickness I CF 3 (CF 2 ) 7 S 3 Degree of segregation is dependent upon lenght of fluoronated counter ion

18 RBS Spectra of N-xy Sulfonate in PHS N S 2 CF 3 Si Air H S Collaboration with G. Barclay, Shipley Heavy Atoms: Sb (51), As (75), Br (79), I (127) Light Atoms: C (12), N (14), (16), F (18), S (32)

19 RBS Spectra of Iodonium Triflate in PHS CF 3 S 3 I Si Air H Si Air

20 Distribution of Non-Polar PAGs in PHS Copolymers Uniform Distribution Si Air Br-1 Br-2 Br Br S 2 S 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 H 70/30 Non-uniform Distribution Br-3 Br S 2 CF 2 CF 2 CF 2 CF 3 Phase Separation - Insoluble in Matrix Br-4 Br S 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 3

21 Distribution of Non-Polar PAGs in Model 193 Matrices PAG concentration, atomic % wafer c8h17 c4f9 c8f17 air Br S 2 (CH 2 ) 3 Br S 2 (CF 2 ) 3 CF 3 Br S 2 (CF 2 ) 7 CF 3 c8h17 c4f9 c8f Normalized film thickness H Matrix

22 Distribution of Non-Polar PAGs in Model 193 Matrices Br-4 Br S 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 3 Si Air H S I Matrix

23 Comparison of PAG Distribution Different Resist Matrices PHS-tBA IBMA-MMA-tBMA Non Polar Sulfonate PAG Br S 2 (CF 2 ) 3 CF H H Normalized film thickness

24 Dissolution Behavior Incident Light Photoresist Substrate H 70/ Time (A sec) Time (Sec)

25 Dissolution Behavior of Matrix Containing Model PAG H 3 C F 3 CF 2 CF 2 CF 2 C 2 S H 3 C Br H 70/ Time (sec) Time (sec)