US009383646B2  (IO)  Patent No.:  US 9,383,646 B2  (45)  Date of Patent:  *Jul. 5, 2016  c12)  United States Patent  Robinson et al.  (54)  TWO-STEP PHOTORESIST COMPOSITIONS  AND METHODS  (71)  Applicants:Alex  Philip Graham Robinson,  Birmingham (GB);  Andreas  Frommhold,  Am Hermsdorfer Anger  (DE);  Alan G. Brown,  Malvern (GB);  Thomas Lada,  Somerville, MA (US)  (72)  Inventors:  Alex Philip Graham Robinson,  Birmingham (GB);  Andreas  Frommhold,  Am Hermsdorfer Anger  (DE);  Alan G. Brown,  Malvern (GB);  Thomas Lada,  Somerville, MA (US)  (73)  Assignee:  IRRESISTIBLE MATERIALS LTD,  Swansea, Wiles (GB)  ( *)  Notice:  Subject to any disclaimer, the term ofthis  patent is extended or adjusted under 35  U.S.C. 154(b) by  O  days.  This patent is subject to a terminal dis› claimer.  (21)  Appl. No.:  14/516,472  (22)  Filed:  Oct.16, 2014  (63)  Continuation of application No. 14/187,649, filed on  Feb. 24, 2014.  (51)  Int. Cl.  (52)  U.S. Cl.  CPC ..............  G03F  710384  (2013.01);  G03F  71038  (58)  Field of Classification Search  CPC ......... G03F 7/004; G03F 7/027; G03F 7/039;  G03F 7/0392; G03F 7/20; G03F 7/32; G03F  7/38; G03F 7/40  See application file for complete search history.  (2013.01);  G03F  710382  (2013.01);  G03F  712024  (2013.01);  G03F  7138  (2013.01)  (65)  Prior Publication Data  Related U.S. Application Data  (57)  ABSTRACT  U.S. PATENT DOCUMENTS  (56)  References Cited  14 Claims, 5 Drawing Sheets  US 2015/0241773 Al  Aug. 27, 2015  The present disclosure relates to novel two-step photoresist  compositions and processes. The processes involve removing  acid-labile groups in step one and crosslinking the remaining  material with themselves or added crosslinking systems in  step two. The incorporation of a multistep pathway in the  resist catalytic chain increases the chemical gradient in areas  receiving a low dose ofirradiation, effectively acting as a built  in dose depend quencher-analog and thus enhancing chemi› cal gradient and thus resolution. The photoresist composi› tions and the methods are ideal for fine pattern processing  using, for example, ultraviolet radiation, beyond extreme  ultraviolet radiation, extreme ultraviolet radiation, X-rays  and charged particle rays. Dual functionality photosensitive  compositions and methods are also disclosed.  Primary Examiner  - Anca Eoff  * cited by examiner  (74)  Attorney, Agent, or Firm  - The Patent Practice of  Szmanda & Shelnut LLC; James G. Shelnut; Charles R.  Szmanda  6,114,082 A  *  6,190,829 Bl*  2008/0261150 Al*  2012/0251953 Al*  2013/0129988 Al*  2014/0255849 Al*  9/2000 Hakey et al ................ 430/270.1  2/2001 Holmes et al. ............. 430/270.1  10/2008 Tsubaki et al. ............ 430/270.1  10/2012 Robinson et al. .......... 430/285 .1  5/2013 Yasuda et al. .............. 428/195.1  9/2014 Robinson et al. .......... 430/285.1  G03F  71039  G03F  71038  G03F  7120  G03F  7138  (2006.01)  (2006.01)  (2006.01)  (2006.01) 