Ionic outgassing from photoresist compositions upon irradiation at 13.5 nm

Transcription

1 Ionic outgassing from photoresist compositions upon irradiation at 13.5 nm Grace H. Ho, Chih- Jen Liu, Chih- Han Yen, Ming- Hsuan Ho, Shih-Yu Wu, and Yu-Hsian Shih Department of Applied Chemistry National University of Kaohsiung Kaohsiung 811, Taiwan

2 1. Introduction Outgassing studies by different approaches:

3 1. Introduction Benchmarked (round robin) resist : ESCAP-type Bis(tert-butylphenyl)iodonium perfluoro-1-butanesulfonate K. R. Dean, et al., Proc. SPIE Vol P (2007)

4 1. Introduction Benchmarking resist outgassing rates: - Evaluation by eight institutes. - Lump sum over outgassing species of collection. - Rates ranging over four orders of magnitude. (a) (b) 1.E+13 1.E+14 1.E+15 1.E+16 1.E+17 1.E+18 Molecules/cm 2 Prod Tool (0.4 W/cm 2 ) (a) K. R. Dean, et al., Proc. SPIE 6519 (2007) 65191P. (b) K. R. Dean, et al., Proc. SPIE 6153 (2007) 61531E.

5 1. Introduction ITRS, 2007 ed. for overall outgassing rates: For 2 min (under the lens) exposure - Organic materials, 5x10 13 molecules/cm 2 -s - Si-containing materials, 5x10 13 molecules/cm 2 -s How much is too much? K. R. Dean, et al. J. Photopolym. Sci. Technol. 20 (2007) Most frequent outgassing species (TD/GC-MS) C 6 H 6, C 4 H 8, C 12 H 18, (C 4 H 9 )C 6 H 5, CH 3 CHO, C 9 H 10, C 6 H 10 O, C 4 H 10 O. - Additional outgassing detected (QMS) CO 2, CO, SO 2 /HSO, organosilicon, HF.

6 1. Introduction 13.5 nm = ev, Γ ion 1, ionic outgassing? - This work started from a strange result. Intensity (a. u) F + EUV R&D resist, provided by Tokyo Ohka Kogyo Co., Ltd. CF + CH 3 O + C n H m + CF 3 + Mass number (u)

7 2. Experimental Solvent PGME, MAK, and PGMEA (from TOK) - Absolute photoabsorption cross, photoionization quantum yield, and ion products. 18 photoacid generators (from Aldrich) - Relative extent of F + outgassing and total ion yield. X - film provided by Nissan Chemicals - Relative extent of of F + and C n H m + outgassing.

8 2. Experimental - Solvent Lambert Beer s law: Photoabsorption cell σ abs Double ion chamber Γ ion Effusive gas SR light I 0 /I i 2 i 1 Carbon foil QMS Direct counting/summing by QMS Ion products Ion detector

9 2. Experimental PAG and X-film X-Y-Z manipulator transporting samples Taped samples SR QMS Synchrotron radiation at 13.5 nm (91.84 ev) BL-08A-LSGM, NSRRC

10 2. Experimental Nine of eighteen PAGs measured of this work PAG of the round-robin resist

11 3. Results - Solvents Photoabosrption Photoionization

12 3. Results - Solvents a Center for X-ray Optics, b J. A. R. Samson, et al., J. Electron Spectrosc. Rel. Phenom. 123, 265 (2002). Photoabsorption: Ion production: PGME ~ MAK < PGMEA PGME ~ MAK < PGMEA ( 8.6 ~ 8.8 < 11.6 Mb)

13 3. Results - Solvents PGMEA MAK PGME

14 3. Results - Solvents PGMEA, MAK, and PGME photoionization at 13.5 nm Γ ion ~ CH 3 CO +, CH 3 OCH 2+, and C n H m + are common ions. - (Major ions+ C n H m+ ) account for most ion products. Molecular ions from MAK photoionization. -CH 3 C(O)CH 3+, C 4 H 10+, and CH 3 C(O)C 5 H 11+. Hydronium ions from PGME. -(CH 3 ) 2 OH + and H 3 O +.

15 3. Results Photoacid generators Ionic outgassing of PAG upon 13.5 nm irradiation F + C x F y + (C 6 H 5 ) 2 S + F + C x F y+, C n H m + I +

16 3. Results Photoacid generators Ionic outgassing from PAGs Relative total ionic outgassing - Relative to F + outgassing of (C 6 H 5 ) 3 S + C 4 F 9 SO 3-.

17 3. Results Photoacid generators + neutral fragments + C 6 H 5

18 3. Results Photoacid generators Ionic outgassing from PAGs Relative extent of F + outgassing through samples

19 3. Results Photoacid generators Relative extent of F + outgassing

20 3. Results Photoacid generators Relative extent of F + outgassing vs. % of F photoabsorption =100 % F photoabsorption overall photoabsorption A property determined by the sum of photoabsorption coefficients of the atomic elements. : Tris(4-tert-butylphenyl)sulfonium Δ: Bis(4-tert-butylphenyl)iodonium More neutral products?

21 3. Results X film from Nissan Chemicals Relative intensity (a. u.) M@19 M@29 M@15 #A #B #C #D #E #F #G #H #I Through sample The extent of ionic outgassing: - polyacrylate > polyester - aliphatic > aromatic (styrene)

22 4. Brief Summary The importance of ionic outgassing - Γ ion of solvents, Direct counting / summing - Solvent: σ abs, Γ ion, and dissociative photoionization. - PAGs: Relative F + outgassing and total ion products. - X-film: Relative CH 3+, F +, and C 2 H + 5 outgassing. (Major ions + C n H m+ ) - Solvent: CH 3 CO +, CH 3 OCH 2+, and C n H m+. - PAGs: F +, C x F y+, (and C n H m+ ). - X-Films: F +, C n H m+.

23 Acknowledgement National Synchrotron Radiation Research Center - Dr. B. M. Cheng and Dr. H. S Fung National Science Council - NSC M CC3 (endorsed by Tokyo Ohka Kogyo) - NSC M Nissan Chemical Industries, Ltd. - Mr. R. Sakamoto, Mr. T. Endo, Mr. Matte Lu and Dr. Bang-Ching Ho - NUK