20:
415:
66:. Currently, mask aligners are still used in academia and research, as projects often involve devices made using photolithography in smaller batches. In a mask aligner, there is a one-to-one correspondence between the mask pattern and the wafer pattern. The mask covers the entire surface of the wafer which is exposed in its entirety in one shot. This was the standard for the 1:1 mask aligners that were succeeded by
141:
in concept, but with one key difference. The aligner uses a mask that holds the pattern for the entire wafer, which may require large masks. The stepper uses a smaller mask on the wafer repeatedly, and steps across the surface to repeat the pattern of the chip layer. This reduces mask costs
96:
in 1973, held the mask entirely separate from the chip and made the adjustment of the image much simpler. Through these stages of development, yields improved from perhaps 10% to about 70%, leading to a corresponding reduction in chip prices.
146:
or mask designs in a single run. More importantly, by focussing the light source onto a single area of the wafer, the stepper can produce much higher resolutions, thus allowing for smaller features on chips
151:). The disadvantage to the stepper is that each chip on the wafer has to be individually imaged, and thus the process of exposing the wafer as a whole is much slower.
119:
Mask holder, placing the mask immediately above the wafer. Relative position between the wafer and the mask can be adjusted using a typical microscope stage mechanism.
234:
59:. The "alignment" refers to the ability to place the mask over precisely the same location repeatedly as the chip goes through multiple rounds of lithography.
81:
placed the mask in direct contact with the top surface of the wafer, which often damaged the pattern when the mask was lifted off again. Used only briefly,
85:
held the mask slightly above the surface to avoid this problem, but were difficult to work with and required considerable manual adjustment. Finally, the
391:
475:
456:
370:
343:
183:
480:
226:
62:
Aligners were a major part of IC manufacture from the 1960s into the late 1970s, when they began to be replaced by the
291:
360:
333:
449:
207:
143:
122:
UV light source, which illuminates through the photomask to project its shadow onto the wafer below.
109:
Microscope, used to see the position of the wafer substrate and mask, and their relative alignment
430:
442:
422:
308:
148:
8:
113:
201:
40:
19:
366:
339:
287:
189:
179:
44:
24:
281:
426:
255:
469:
193:
52:
93:
173:
71:
56:
77:
There are several distinct generations of aligner technology. The early
86:
48:
178:. Paula Kepos, Thomson Gale. Detroit, Mich.: St. James Press. 1993.
138:
132:
116:), used to immobilize the wafer, often using a vacuum line below.
67:
63:
414:
142:
dramatically and allows a single wafer to be used for different
55:
while a bright light is shone through the mask and onto the
362:
Integrated
Circuit Packaging, Assembly and Interconnections
280:
Rizvi, Syed (2005). "1.3 The
Technology History of Masks".
227:"History of The Perkin-Elmer Corporation – FundingUniverse"
105:
A typical mask aligner consists of the following parts:
248:
175:
International directory of company histories. Vol. 7
467:
392:"The Near Impossibility of Making a Microchip"
300:
283:Handbook of Photomask Manufacturing Technology
450:
332:Lu, Daniel; Wong, C. P. (17 December 2008).
16:Aligns a photomask with features on a wafer
457:
443:
126:
137:The projection aligner is similar to the
18:
389:
468:
331:
358:
306:
279:
237:from the original on February 4, 2013
409:
221:
219:
217:
168:
166:
164:
13:
14:
492:
383:
309:"Semiconductor Photo Lithography"
214:
161:
413:
359:Greig, William (24 April 2007).
335:Materials for Advanced Packaging
476:Lithography (microfabrication)
352:
325:
273:
1:
390:Burbank, Daniel (Fall 1999).
154:
100:
429:. You can help Knowledge by
39:, is a system that produces
7:
10:
497:
481:Computer engineering stubs
408:
399:Invention & Technology
307:Brown, Matt (2020-07-01).
286:. CRC Press. p. 728.
144:integrated circuit layouts
130:
231:www.fundinguniverse.com
127:Comparison with stepper
74:with reduction optics.
425:-related article is a
206:: CS1 maint: others (
47:process. It holds the
28:
22:
423:computer-engineering
149:minimum feature size
41:integrated circuits
90:projection aligner
83:proximity aligners
29:
438:
437:
372:978-0-387-33913-9
345:978-0-387-78219-5
185:978-1-55862-648-5
112:Wafer holder (or
488:
459:
452:
445:
417:
410:
402:
396:
377:
376:
356:
350:
349:
329:
323:
322:
320:
319:
304:
298:
297:
277:
271:
270:
268:
267:
252:
246:
245:
243:
242:
223:
212:
211:
205:
197:
170:
92:, introduced by
79:contact aligners
45:photolithography
27:MA6 mask aligner
496:
495:
491:
490:
489:
487:
486:
485:
466:
465:
464:
463:
406:
394:
386:
381:
380:
373:
357:
353:
346:
330:
326:
317:
315:
305:
301:
294:
278:
274:
265:
263:
254:
253:
249:
240:
238:
225:
224:
215:
199:
198:
186:
172:
171:
162:
157:
135:
129:
103:
43:(IC) using the
17:
12:
11:
5:
494:
484:
483:
478:
462:
461:
454:
447:
439:
436:
435:
418:
404:
403:
385:
384:External links
382:
379:
378:
371:
351:
344:
324:
299:
292:
272:
247:
213:
184:
159:
158:
156:
153:
131:Main article:
128:
125:
124:
123:
120:
117:
110:
102:
99:
15:
9:
6:
4:
3:
2:
493:
482:
479:
477:
474:
473:
471:
460:
455:
453:
448:
446:
441:
440:
434:
432:
428:
424:
419:
416:
412:
411:
407:
400:
393:
388:
387:
374:
368:
364:
363:
355:
347:
341:
337:
336:
328:
314:
310:
303:
295:
293:9781420028782
289:
285:
284:
276:
261:
257:
256:"Tool Search"
251:
236:
232:
228:
222:
220:
218:
209:
203:
195:
191:
187:
181:
177:
176:
169:
167:
165:
160:
152:
150:
145:
140:
139:wafer stepper
134:
121:
118:
115:
111:
108:
107:
106:
98:
95:
91:
88:
84:
80:
75:
73:
69:
65:
60:
58:
54:
53:silicon wafer
50:
46:
42:
38:
34:
26:
25:SÜSS MicroTec
21:
431:expanding it
420:
405:
398:
365:. Springer.
361:
354:
338:. Springer.
334:
327:
316:. Retrieved
312:
302:
282:
275:
264:. Retrieved
262:. 2019-09-10
259:
250:
239:. Retrieved
230:
174:
136:
104:
94:Perkin-Elmer
89:
82:
78:
76:
61:
37:mask aligner
36:
32:
30:
260:Harvard CNS
57:photoresist
470:Categories
318:2024-04-30
266:2024-04-30
241:2022-12-25
155:References
101:Components
313:Inseto UK
202:cite book
194:769042405
87:Micralign
51:over the
49:photomask
235:Archived
72:scanners
68:steppers
133:Stepper
64:stepper
33:aligner
369:
342:
290:
192:
182:
421:This
395:(PDF)
114:chuck
35:, or
427:stub
367:ISBN
340:ISBN
288:ISBN
208:link
190:OCLC
180:ISBN
70:and
31:An
472::
397:.
311:.
258:.
233:.
229:.
216:^
204:}}
200:{{
188:.
163:^
23:A
458:e
451:t
444:v
433:.
401:.
375:.
348:.
321:.
296:.
269:.
244:.
210:)
196:.
147:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
