375:
error factor begins to exceed one, i.e., the dimension error on the wafer may be more than 1/4 the dimension error on the mask, and the second is that the mask feature is becoming smaller, and the dimension tolerance is approaching a few nanometers. For example, a 25 nm wafer pattern should correspond to a 100 nm mask pattern, but the wafer tolerance could be 1.25 nm (5% spec), which translates into 5 nm on the photomask. The variation of electron beam scattering in directly writing the photomask pattern can easily well exceed this.
388:
patterns so that moderate-to-small sized particles that land on the pellicle will be too far out of focus to print. Although they are designed to keep particles away, pellicles become a part of the imaging system and their optical properties need to be taken into account. Pellicles material are
Nitrocellulose and made for various Transmission Wavelengths. Current pellicles are made from polysilicon, and companies are exploring other materials for high-NA EUV and future chip making processes.
20:
392:
28:
178:
94:)) and the unwanted rubylith was peeled off by hand, forming the master image of that layer of the chip, often called "artwork". Increasingly complex and thus larger chips required larger and larger rubyliths, eventually even filling the wall of a room, and artworks were to be photographically reduced to produce photomasks (Eventually this whole process was replaced by the
383:
The term "pellicle" is used to mean "film", "thin film", or "membrane." Beginning in the 1960s, thin film stretched on a metal frame, also known as a "pellicle", was used as a beam splitter for optical instruments. It has been used in a number of instruments to split a beam of light without causing
374:
Leading-edge photomasks (pre-corrected) images of the final chip patterns are magnified by four times. This magnification factor has been a key benefit in reducing pattern sensitivity to imaging errors. However, as features continue to shrink, two trends come into play: the first is that the mask
119:
off the wafer and onto the photomask and it had to be cleaned or discarded. This drove the adoption of reverse master photomasks (see above), which were used to produce (with contact photolithography and etching) the needed many actual working photomasks. Later, projection photo-lithography meant
346:
has a strong impact on photomask requirements. The commonly used attenuated phase-shifting mask is more sensitive to the higher incidence angles applied in "hyper-NA" lithography, due to the longer optical path through the patterned film. During manufacturing, inspection using a special form of
387:
Particle contamination can be a significant problem in semiconductor manufacturing. A photomask is protected from particles by a pellicle – a thin transparent film stretched over a frame that is glued over one side of the photomask. The pellicle is far enough away from the mask
299:" from position to position under the optical column or the stepper lens until full exposure of the wafer is achieved. A photomask with several copies of the integrated circuit design is used to reduce the number of steppings required to expose the entire wafer, thus increasing productivity.
181:
A simulated photomask. The thicker features are the integrated circuit that is desired to be printed on the wafer. The thinner features are assists that do not print themselves but help the integrated circuit print better out-of-focus. The zig-zag appearance of the photomask is because
291:
circuit. (However, some photolithography fabrications utilize reticles with more than one layer placed side by side onto the same mask, used as copies to create several identical integrated circuits from one photomask). In modern usage, the terms reticle and photomask are synonymous.
338:
found that thinner absorbers degrade image contrast and therefore contribute to line-edge roughness, using state-of-the-art photolithography tools. One possibility is to eliminate absorbers altogether and use "chromeless" masks, relying solely on phase-shifting for imaging.
384:
an optical path shift due to its small film thickness. In 1978, Shea et al. at IBM patented a process to use the "pellicle" as a dust cover to protect a photomask or reticle. In the context of this entry, "pellicle" means "thin film dust cover to protect a photomask".
107:
The reticle was by step-and-repeater photolithography and etching used to produce a photomask with image-size the same as the final chip. The photomask might be used directly in the fab or be used as master-photomask to produce the final actual working photomasks.
70:. A curvilinear photomask has patterns with curves, which is a departure from conventional photomasks which only have patterns that are completely vertical or horizontal, known as manhattan geometry. These photomasks require special equipment to manufacture.
309:
to enhance the image quality to acceptable values. This can be achieved in many ways. The two most common methods are to use an attenuated phase-shifting background film on the mask to increase the contrast of small intensity peaks, or to etch the exposed
275:. In the case of a photomask, there is a one-to-one correspondence between the mask pattern and the wafer pattern. The mask covered the entire surface of the wafer which was exposed in its entirety in one shot. This was the standard for the 1:1
500:. As many as 30 masks (of varying price) may be required to form a complete mask set. As modern chips are built in several layers stacked on top of each other, at least one mask is required for each of these layers.
418:
Mask
Industry Assessment which includes current industry analysis and the results of their annual photomask manufacturers survey. The following companies are listed in order of their global market share (2009 info):
796:
314:
so that the edge between the etched and unetched areas can be used to image nearly zero intensity. In the second case, unwanted edges would need to be trimmed out with another exposure. The former method is
884:
490:
The worldwide photomask market was estimated as $ 3.2 billion in 2012 and $ 3.1 billion in 2013. Almost half of the market was from captive mask shops (in-house mask shops of major chipmakers).
295:
In a modern stepper or scanner, the pattern in the photomask is projected and shrunk by four or five times onto the wafer surface. To achieve complete wafer coverage, the wafer is repeatedly "
334:, photomask features that are 4× larger must inevitably shrink as well. This could pose challenges since the absorber film will need to become thinner, and hence less opaque. A 2005 study by
849:
347:
microscopy called CD-SEM (Critical-Dimension
Scanning Electron Microscopy) is used to measure critical dimensions on photomasks which are the dimensions of the patterns on a photomask.
95:
287:
with reduction optics. As used in steppers and scanners which use image projection, the reticle commonly contains only one copy, also called one layer of the designed
945:
1037:
1192:
Capital-intensive industry. Investment levels….. – ~$ 40M for 'conventional' (180-nm node or above) – >$ 100M for 'advanced' (130-nm node and beyond)
493:
The costs of creating new mask shop for 180 nm processes were estimated in 2005 as $ 40 million, and for 130 nm - more than $ 100 million.
1175:
729:
1260:
319:, and is often considered a weak enhancement, requiring special illumination for the most enhancement, while the latter method is known as
514:
976:
1205:
213:, 248 nm, and 193 nm. Photomasks have also been developed for other forms of radiation such as 157 nm, 13.5 nm (
43:) is an opaque plate with transparent areas that allow light to shine through in a defined pattern. Photomasks are commonly used in
66:
In photolithography, several masks are used in turn, each one reproducing a layer of the completed design, and together known as a
1255:
883:
Eom, Tae-Seung; Lim, Chang M.; Kim, Seo-Min; Kim, Hee-Bom; Oh, Se-Young; Ma, Won-Kwang; Moon, Seung-Chan; Shin, Ki S. (2003).
1061:
Hughes, Greg; Henry Yun (2009-10-01). "Mask industry assessment: 2009". In
Zurbrick, Larry S.; Montgomery, M. Warren (eds.).
780:
705:
675:
649:
1024:
770:
952:
665:
639:
472:
111:
As feature size shrank, the only way to properly focus the image was to place it in direct contact with the wafer. These
931:
355:
754:
237:
214:
98:
to produce the master image). At this point the master image could be arrayed into a multi-chip image called a
288:
183:
525:
86:
sheet was used. The design of one layer was cut into the rubylith, initially by hand on an illuminated
496:
The purchase price of a photomask, in 2006, could range from $ 250 to $ 100,000 for a single high-end
885:"Comparative study of chromeless and attenuated phase shift mask for 0.3-k 1 ArF lithography of DRAM"
509:
152:
23:
A photomask. This photomask has 20 copies, also called layers, of the same circuit pattern or design.
1184:
1114:
625:
276:
343:
1066:
302:
160:
1177:
An
Analysis of the Economics of Photomask Manufacturing Part – 1: The Economic Environment
8:
1237:
1025:
https://community.cadence.com/cadence_blogs_8/b/breakfast-bytes/posts/what-is-high-na-euv
423:
249:
112:
1174:
Weber, Charles M.; Berglund, C. Neil (February 9, 2005). "The Mask Shop's
Perspective".
1070:
1228:
1102:
1090:
900:
865:
723:
607:
260:
172:
48:
31:
A schematic illustration of a photomask (top) and an IC layer printed using it (bottom)
1082:
970:
904:
869:
809:
776:
750:
711:
701:
671:
645:
599:
578:
Diaz, S.L.M.; Fowler, J.W.; Pfund, M.E.; Mackulak, G.T.; Hickie, M. (November 2005).
554:
480:
148:
1094:
611:
358:
work by reflecting light, which is achieved by using multiple alternating layers of
1232:
1220:
1074:
892:
857:
591:
580:"Evaluating the Impacts of Reticle Requirements in Semiconductor Wafer Fabrication"
497:
439:
306:
229:; but these require entirely new materials for the substrate and the pattern film.
44:
744:
520:
464:
456:
256:
199:
391:
163:
systems which generate reticles directly from the original computerized design.
1206:"Mask Cost and Profitability in Photomask Manufacturing: An Empirical Analysis"
579:
535:
530:
434:
87:
810:
Lithography experts back higher magnification in photomasks to ease challenges
715:
1249:
1086:
603:
484:
327:
233:
151:
were introduced. The original pattern generators have since been replaced by
132:
1224:
595:
695:
252:
techniques, a photomask would correspond to a subset of the layer pattern.
191:
140:
136:
284:
245:
124:
photo-lithography used reticles directly and ended the use of photomasks.
19:
116:
850:"Chromeless phase-shifted masks: A new approach to phase-shifting masks"
359:
331:
128:
1078:
896:
848:
Toh, Kenny K.; Dao, Giang T.; Singh, Rajeev R.; Gaw, Henry T. (1991).
861:
405:
222:
210:
1129:
120:
photomask lifetime was indefinite. Still later direct-step-on-wafer
27:
415:
195:
144:
79:
1153:"SEMI Reports 2013 Semiconductor Photomask Sales of $ 3.1 Billion"
104:. The reticle was originally a 10X larger image of a single chip.
1152:
476:
363:
296:
280:
241:
177:
91:
56:
1130:"Semiconductor Photomask Market: Forecast $ 3.5 Billion in 2014"
209:
metal absorbing film. Photomasks are used at wavelengths of 365
59:). In semiconductor manufacturing, a mask is sometimes called a
428:
311:
1203:
1015:
W-H. Cheng and J. Farnsworth, Proc. SPIE 6607, 660724 (2007).
452:
399:
218:
156:
83:
52:
1204:
Weber, C.M; Berglund, C.N.; Gabella, P. (13 November 2006).
743:
Rizvi, Syed (2005). "1.3 The
Technology History of Masks".
468:
411:
335:
226:
1183:. ISMT Mask Automation Workshop. p. 6. Archived from
78:
For IC production in the 1960s and early 1970s, an opaque
932:"CD-SEM: Critical-Dimension Scanning Electron Microscope"
460:
323:, and is the most popular strong enhancement technique.
577:
369:
414:
Annual
Conference, Photomask Technology reports the
1150:
263:devices, there was a distinction between the term
190:Lithographic photomasks are typically transparent
127:Photomask materials changed over time. Initially
1247:
1213:IEEE Transactions on Semiconductor Manufacturing
584:IEEE Transactions on Semiconductor Manufacturing
483:, have their own large maskmaking facilities or
51:(ICs or "chips") to produce a pattern on a thin
1060:
305:150 nm or below in size generally require
847:
828:
746:Handbook of Photomask Manufacturing Technology
667:Handbook of Photomask Manufacturing Technology
1173:
1151:Tracy, Dan; Deborah Geiger (April 14, 2014).
1065:. Vol. 7488. pp. 748803–748803–13.
1035:
248:, and individually selected for exposure. In
194:plates covered with a pattern defined with a
882:
515:Integrated circuit layout design protection
186:was applied to it to create a better print.
728:: CS1 maint: location missing publisher (
644:. John Wiley & Sons. 29 October 2010.
400:Leading commercial photomask manufacturers
911:
815:
255:Historically in photolithography for the
1127:
390:
176:
26:
18:
1132:. SEMI Industry Research and Statistics
693:
1248:
975:: CS1 maint: archived copy as title (
891:. Vol. 5040. pp. 1310–1320.
626:"The Quest for Curvilinear Photomasks"
742:
854:10th Annual Symp on Microlithography
689:
687:
370:Mask error enhancement factor (MEEF)
1261:Semiconductor fabrication equipment
487:with the abovementioned companies.
321:alternating-aperture phase-shifting
236:, each defining a pattern layer in
13:
856:. Vol. 1496. pp. 27–53.
350:
82:film laminated onto a transparent
14:
1272:
993:, Proc. SPIE 7140, 714007 (2008).
684:
240:, is fed into a photolithography
641:Introduction to Microfabrication
1197:
1167:
1144:
1121:
1054:
1038:"Optical behavior of pellicles"
1036:Chris A. Mack (November 2007).
1029:
1018:
1009:
996:
983:
938:
924:
921:, vol. 5992, pp. 306-316 (2005)
876:
841:
838:, vol. 5853, pp. 243-251 (2005)
803:
700:. Ankaj Gupta. Abingdon, Oxon.
1256:Lithography (microfabrication)
1128:Chamness, Lara (May 7, 2013).
1006:, Proc. SPIE 5256, 673 (2003).
825:, vol. 4889, pp. 50-58 (2002).
789:
763:
736:
697:Integrated circuit fabrication
658:
632:
618:
571:
547:
238:integrated circuit fabrication
1:
670:. CRC Press. 3 October 2018.
541:
395:Pellicle Mounting Machine MLI
889:Optical Microlithography XVI
852:. In Wiley, James N. (ed.).
378:
184:optical proximity correction
147:which has better opacity to
7:
1238:doi:10.1109/TSM.2006.883577
526:Nanochannel glass materials
503:
166:
10:
1277:
749:. CRC Press. p. 728.
403:
170:
143:to control expansion, and
73:
1063:Photomask Technology 2009
887:. In Yen, Anthony (ed.).
772:Principles of Lithography
694:Shubham, Kumar n (2021).
510:Computational lithography
451:Major chipmakers such as
317:attenuated phase-shifting
153:electron beam lithography
115:often lifted some of the
96:optical pattern generator
1225:10.1109/TSM.2006.883577
596:10.1109/TSM.2005.858502
555:"Reticle Manufacturing"
444:Taiwan Mask Corporation
279:that were succeeded by
159:-driven mask writer or
1042:Microlithography World
396:
187:
47:for the production of
39:(also simply called a
32:
24:
16:Photolithographic tool
834:M. Yoshizawa et al.,
394:
344:immersion lithography
180:
55:of material (usually
30:
22:
775:. SPIE Press. 2005.
161:maskless lithography
1071:2009SPIE.7488E..03H
917:C. A. Mack et al.,
424:Dai Nippon Printing
90:(later by machine (
49:integrated circuits
397:
261:integrated circuit
188:
173:Photographic plate
33:
25:
1240:; page 23 table 1
1079:10.1117/12.832722
897:10.1117/12.485452
782:978-0-8194-5660-1
707:978-1-000-39644-7
677:978-1-4200-2878-2
651:978-1-119-99189-2
481:Micron Technology
342:The emergence of
234:set of photomasks
149:ultraviolet light
1268:
1241:
1236:
1210:
1201:
1195:
1194:
1189:
1182:
1171:
1165:
1164:
1162:
1160:
1148:
1142:
1141:
1139:
1137:
1125:
1119:
1118:
1112:
1108:
1106:
1098:
1058:
1052:
1051:
1049:
1048:
1033:
1027:
1022:
1016:
1013:
1007:
1000:
994:
987:
981:
980:
974:
966:
964:
963:
957:
951:. Archived from
950:
942:
936:
935:
928:
922:
915:
909:
908:
880:
874:
873:
862:10.1117/12.29750
845:
839:
832:
826:
821:Y. Sato et al.,
819:
813:
807:
801:
800:
793:
787:
786:
767:
761:
760:
740:
734:
733:
727:
719:
691:
682:
681:
662:
656:
655:
636:
630:
629:
628:. 15 April 2021.
622:
616:
615:
575:
569:
568:
566:
565:
551:
517:(or "Mask work")
498:phase-shift mask
440:Hoya Corporation
326:As leading-edge
250:multi-patterning
113:contact aligners
45:photolithography
1276:
1275:
1271:
1270:
1269:
1267:
1266:
1265:
1246:
1245:
1244:
1208:
1202:
1198:
1190:on 2016-03-03.
1187:
1180:
1172:
1168:
1158:
1156:
1149:
1145:
1135:
1133:
1126:
1122:
1110:
1109:
1100:
1099:
1059:
1055:
1046:
1044:
1034:
1030:
1023:
1019:
1014:
1010:
1001:
997:
988:
984:
968:
967:
961:
959:
955:
948:
946:"Archived copy"
944:
943:
939:
930:
929:
925:
916:
912:
881:
877:
846:
842:
833:
829:
820:
816:
812:// EETimes 2000
808:
804:
795:
794:
790:
783:
769:
768:
764:
757:
741:
737:
721:
720:
708:
692:
685:
678:
664:
663:
659:
652:
638:
637:
633:
624:
623:
619:
576:
572:
563:
561:
553:
552:
548:
544:
521:Mask inspection
506:
457:Globalfoundries
408:
402:
381:
372:
353:
351:EUV lithography
271:, and the term
257:mass production
207:
203:
175:
169:
135:opacity. Later
76:
17:
12:
11:
5:
1274:
1264:
1263:
1258:
1243:
1242:
1219:(4): 465–474.
1196:
1166:
1143:
1120:
1111:|journal=
1053:
1028:
1017:
1008:
995:
982:
937:
923:
910:
875:
840:
827:
814:
802:
788:
781:
762:
755:
735:
706:
683:
676:
657:
650:
631:
617:
590:(4): 622–632.
570:
545:
543:
540:
539:
538:
536:Stepping level
533:
531:SMIF interface
528:
523:
518:
512:
505:
502:
485:joint ventures
449:
448:
445:
442:
437:
435:Photronics Inc
432:
426:
404:Main article:
401:
398:
380:
377:
371:
368:
356:EUV photomasks
352:
349:
307:phase-shifting
205:
201:
168:
165:
131:was used with
88:drafting table
75:
72:
15:
9:
6:
4:
3:
2:
1273:
1262:
1259:
1257:
1254:
1253:
1251:
1239:
1234:
1230:
1226:
1222:
1218:
1214:
1207:
1200:
1193:
1186:
1179:
1178:
1170:
1154:
1147:
1131:
1124:
1116:
1104:
1096:
1092:
1088:
1084:
1080:
1076:
1072:
1068:
1064:
1057:
1043:
1039:
1032:
1026:
1021:
1012:
1005:
999:
992:
989:E. Hendrickx
986:
978:
972:
958:on 2017-06-02
954:
947:
941:
933:
927:
920:
914:
906:
902:
898:
894:
890:
886:
879:
871:
867:
863:
859:
855:
851:
844:
837:
831:
824:
818:
811:
806:
798:
792:
784:
778:
774:
773:
766:
758:
756:9781420028782
752:
748:
747:
739:
731:
725:
717:
713:
709:
703:
699:
698:
690:
688:
679:
673:
669:
668:
661:
653:
647:
643:
642:
635:
627:
621:
613:
609:
605:
601:
597:
593:
589:
585:
581:
574:
560:
556:
550:
546:
537:
534:
532:
529:
527:
524:
522:
519:
516:
513:
511:
508:
507:
501:
499:
494:
491:
488:
486:
482:
478:
474:
470:
466:
462:
458:
454:
447:Compugraphics
446:
443:
441:
438:
436:
433:
430:
427:
425:
422:
421:
420:
417:
413:
407:
393:
389:
385:
376:
367:
365:
361:
357:
348:
345:
340:
337:
333:
329:
328:semiconductor
324:
322:
318:
313:
308:
304:
300:
298:
293:
290:
286:
282:
278:
277:mask aligners
274:
270:
266:
262:
258:
253:
251:
247:
243:
239:
235:
230:
228:
224:
220:
216:
212:
208:
197:
193:
185:
179:
174:
164:
162:
158:
154:
150:
146:
142:
138:
134:
133:silver halide
130:
125:
123:
118:
114:
109:
105:
103:
102:
97:
93:
89:
85:
81:
71:
69:
64:
62:
58:
54:
50:
46:
42:
38:
29:
21:
1216:
1212:
1199:
1191:
1185:the original
1176:
1169:
1157:. Retrieved
1146:
1134:. Retrieved
1123:
1062:
1056:
1045:. Retrieved
1041:
1031:
1020:
1011:
1003:
998:
990:
985:
960:. Retrieved
953:the original
940:
926:
918:
913:
888:
878:
853:
843:
835:
830:
822:
817:
805:
791:
771:
765:
745:
738:
696:
666:
660:
640:
634:
620:
587:
583:
573:
562:. Retrieved
558:
549:
495:
492:
489:
450:
409:
386:
382:
373:
354:
341:
325:
320:
316:
301:
294:
272:
268:
265:photoreticle
264:
254:
231:
192:fused silica
189:
141:fused silica
137:borosilicate
126:
121:
110:
106:
100:
99:
77:
67:
65:
60:
40:
36:
34:
1159:6 September
1136:6 September
117:photoresist
1250:Categories
1047:2008-09-13
1002:C-J. Chen
962:2019-06-23
919:Proc. SPIE
836:Proc. SPIE
823:Proc. SPIE
716:1246513110
564:2024-01-05
542:References
431:Photomasks
360:molybdenum
267:or simply
171:See also:
129:soda glass
1113:ignored (
1103:cite book
1087:0277-786X
905:109838206
870:109009678
797:"Reticle"
724:cite book
604:0894-6507
406:Mask shop
379:Pellicles
330:features
273:photomask
223:electrons
198:(Cr) or
139:and then
37:photomask
1095:86650806
971:cite web
612:37911295
504:See also
416:SEMATECH
303:Features
285:scanners
281:steppers
196:chromium
167:Overview
145:chromium
80:rubylith
68:mask set
1233:2236552
1067:Bibcode
477:Samsung
364:silicon
297:stepped
269:reticle
246:scanner
242:stepper
122:stepper
101:reticle
92:plotter
74:History
61:reticle
57:silicon
1231:
1155:. SEMI
1093:
1085:
1004:et al.
991:et al.
903:
868:
779:
753:
714:
704:
674:
648:
610:
602:
479:, and
429:Toppan
332:shrink
312:quartz
225:, and
1229:S2CID
1209:(PDF)
1188:(PDF)
1181:(PDF)
1091:S2CID
956:(PDF)
949:(PDF)
901:S2CID
866:S2CID
608:S2CID
453:Intel
219:X-ray
157:laser
84:mylar
53:wafer
1161:2014
1138:2014
1115:help
1083:ISSN
977:link
777:ISBN
751:ISBN
730:link
712:OCLC
702:ISBN
672:ISBN
646:ISBN
600:ISSN
469:TSMC
412:SPIE
410:The
362:and
336:IMEC
289:VLSI
283:and
227:ions
155:and
41:mask
1221:doi
1075:doi
893:doi
858:doi
592:doi
559:KLA
473:UMC
465:NEC
461:IBM
259:of
244:or
217:),
215:EUV
1252::
1227:.
1217:19
1215:.
1211:.
1107::
1105:}}
1101:{{
1089:.
1081:.
1073:.
1040:.
973:}}
969:{{
899:.
864:.
726:}}
722:{{
710:.
686:^
606:.
598:.
588:18
586:.
582:.
557:.
475:,
471:,
467:,
463:,
459:,
455:,
366:.
232:A
221:,
211:nm
200:Fe
63:.
35:A
1235:.
1223::
1163:.
1140:.
1117:)
1097:.
1077::
1069::
1050:.
979:)
965:.
934:.
907:.
895::
872:.
860::
799:.
785:.
759:.
732:)
718:.
680:.
654:.
614:.
594::
567:.
206:3
204:O
202:2
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
