SHARP  imaging  at  high  mask-­‐side  NA    Markus  Benk,  Antoine  Wojdyla,  Kenneth  Goldberg,  Patrick  Naulleau  Lawrence  Berkeley  Na?onal  Laboratory,  One  Cyclotron  Road,  Berkeley,  CA  94720,  USA    

Acknowledgements  • LBNL EUV Program supported by:

EUREKA (Intel, Samsung, TSMC)

Results  Summary  

SHARP  Resolu?on  Limits  

Target  Fabrica?on  

The   performance   of   the   SHARP   microscope   has   been   well  characterized   for   its   low-­‐NA   lenses,   emula?ng   imaging   in   0.25   and  0.33  NA  lithography  scanners.  Evalua?ng  the  resolu?on  of  its  higher-­‐NA   lenses,   intended   to   emulate   future   genera?ons   of   EUV  lithography,  requires  a  photomask  with  features  down  to  22-­‐nm  half  pitch.  We  have   fabricated  an  ultra-­‐high   resolu?on   test  paYern  mask  with  features  down  to  20-­‐nm  hp  to  use  with  SHARP’s  high-­‐NA  zoneplates.  Prin?ng   the   paYern   on   a   mul?layer-­‐coated   silicon   wafer   in   the  Berkeley   Microfield   Exposure   Tool   and   using   metal-­‐oxide   based  photoresist   directly,   as   an   absorber,   is   a   fast   and   economical  approach   to   achieve   the   required   feature   size.  With   this   target  we  have   demonstrated   real-­‐space   imaging   down   to   22   nm   hp   on   the  SHARP  microscope.  

Illumina?on   coherent   incoherent   extreme  dipole  

Resolu?on  limit  (full  cycle)  

0.5  4xNA  108  nm        54  nm  

66  nm    33  nm  

54  nm  (pitch)    27    nm  (hp)  

0.625  4xNA    87  nm      44  nm  

53  nm    26  nm  

44    nm  (pitch)    22    nm  (hp)  

rC =λNA

rR =0.61λNA

rD =0.5λNA

Berkeley  Microfield  Exposure  Tool  BMET  § 0.3  NA  

Inpria YA-Series Resist § Negative-tone § 50-nm absorption length § 30-­‐nm  thick  resist  on    Si-­‐wafer  coated  with  a  standard  mul?layer  § 30%  EUV-­‐transmission  on  double  pass  

b)  SEM  image  of  22-­‐nm  hp  lines  (target  scale)    

a)  SHARP  image  of  100-­‐nm  hp  lines  and  1.5-­‐µm  wide  border  (target  scale)  b)  cross-­‐sec?on  plot,  ver?cally  averaged  over  the  boxed  region  in  (a)  

Image  details  of  dense  ver?cal  lines,  recorded  using  coherent,  incoherent,  and  extreme  dipole  illumina?on.  Line  sizes  are  half-­‐pitch  at  target  scale.  

Image  detail  of  22-­‐nm  hp  lines  (target  scale),  imaged  with  the  0.625  4xNA  zone-­‐plate  and  cross-­‐sec?on  plot  of  this  data,  ver?cally  averaged  over  100  pixels,  covering  1.5  µm.    

Contrast  curves  through  pitch  for  the  image  data  shown  below.  Data  points  below  the  curve  are  due  to  imperfect  alignment.  

0.5  4xNA  

0.625  4xNA  

• Initial SHARP funding by SEMATECH