Abstract

Test patterns in the form of diffraction gratings are used for testing and monitoring linewidths on integrated circuit structures. The first and second diffraction orders produed by a laser beam are evaluated to give the width of the grating lines. Measurements on chrome masks show that this technique is accurate to 5% down to linewidths of 0.5 μm. The design of a test set for factory type mask testing is presented. Also, experiments are reported on the testing of patterns on Si wafers directly after. photoresist development and after various etching steps, and an automatic setup for rapid testing of wafers is described.

© 1980 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. D. E. Davis, J. K. Hassan, M. R. Wojtaszek, at Electrochemical Society Spring Meeting 1978, Seattle, Extended Abstracts 78-1 (1978), p. 906.
  2. D. Nyyssonen, J. M. Jerke, in Proceedings, International Electronic Devices Meeting, Washington, D.C., 4–6 Dec. 1978, p. 437.
  3. D. Nyyssonen, in Developments in Semiconductor Microlithography III, (SPIE, Bellingham, Wash., 1978), Vol. 135, pp. 115–119.
    [Crossref]
  4. D. Nyyssonen, in Developments in Semiconductor Microlithography II (SPIE, Bellingham, Wash., 1977), Vol. 100, pp. 127–134.
    [Crossref]
  5. D. Nyyssonen, Appl. Opt. 16, 2223 (1977).
    [Crossref] [PubMed]
  6. D. A. Swyt, F. Rosberry, D. Nyyssonen, in Proceedings, Kodak Microelectronics Seminar, INTERFACE 1977, Publication G-48 (Eastman Kodak, Rochester, N.Y., 1978).
  7. J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.
  8. H. L. Kasdan, N. George, Developments in Semiconductor Microlithography, (SPIE, Bellingham, Wash., 1976), Vol. 80, pp. 54–63.
    [Crossref]
  9. A. L. Flamholz, R. S. Charsky, in Ref. 3, pp. 120–127.
  10. M. Born, E. Wolf, Principles of Optics (Pergamon, London, 1965).
  11. J. M. Cowley, Diffraction Physics (North-Holland, Amsterdam, 1975).
  12. K. Knop, J. Opt. Soc. Am. 68, 1206 (1978).
    [Crossref]

1978 (1)

1977 (1)

Born, M.

M. Born, E. Wolf, Principles of Optics (Pergamon, London, 1965).

Charsky, R. S.

A. L. Flamholz, R. S. Charsky, in Ref. 3, pp. 120–127.

Cowley, J. M.

J. M. Cowley, Diffraction Physics (North-Holland, Amsterdam, 1975).

Davis, D. E.

D. E. Davis, J. K. Hassan, M. R. Wojtaszek, at Electrochemical Society Spring Meeting 1978, Seattle, Extended Abstracts 78-1 (1978), p. 906.

Flamholz, A. L.

A. L. Flamholz, R. S. Charsky, in Ref. 3, pp. 120–127.

George, N.

H. L. Kasdan, N. George, Developments in Semiconductor Microlithography, (SPIE, Bellingham, Wash., 1976), Vol. 80, pp. 54–63.
[Crossref]

Hartman, A. W.

J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.

Hassan, J. K.

D. E. Davis, J. K. Hassan, M. R. Wojtaszek, at Electrochemical Society Spring Meeting 1978, Seattle, Extended Abstracts 78-1 (1978), p. 906.

Jerke, J. M.

J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.

D. Nyyssonen, J. M. Jerke, in Proceedings, International Electronic Devices Meeting, Washington, D.C., 4–6 Dec. 1978, p. 437.

Kasdan, H. L.

H. L. Kasdan, N. George, Developments in Semiconductor Microlithography, (SPIE, Bellingham, Wash., 1976), Vol. 80, pp. 54–63.
[Crossref]

Keery, W. J.

J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.

Knop, K.

Nyyssonen, D.

D. Nyyssonen, Appl. Opt. 16, 2223 (1977).
[Crossref] [PubMed]

D. Nyyssonen, in Developments in Semiconductor Microlithography III, (SPIE, Bellingham, Wash., 1978), Vol. 135, pp. 115–119.
[Crossref]

D. Nyyssonen, in Developments in Semiconductor Microlithography II (SPIE, Bellingham, Wash., 1977), Vol. 100, pp. 127–134.
[Crossref]

D. Nyyssonen, J. M. Jerke, in Proceedings, International Electronic Devices Meeting, Washington, D.C., 4–6 Dec. 1978, p. 437.

D. A. Swyt, F. Rosberry, D. Nyyssonen, in Proceedings, Kodak Microelectronics Seminar, INTERFACE 1977, Publication G-48 (Eastman Kodak, Rochester, N.Y., 1978).

J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.

Rosberry, F.

D. A. Swyt, F. Rosberry, D. Nyyssonen, in Proceedings, Kodak Microelectronics Seminar, INTERFACE 1977, Publication G-48 (Eastman Kodak, Rochester, N.Y., 1978).

Swing, R. E.

J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.

Swyt, D. A.

D. A. Swyt, F. Rosberry, D. Nyyssonen, in Proceedings, Kodak Microelectronics Seminar, INTERFACE 1977, Publication G-48 (Eastman Kodak, Rochester, N.Y., 1978).

Wojtaszek, M. R.

D. E. Davis, J. K. Hassan, M. R. Wojtaszek, at Electrochemical Society Spring Meeting 1978, Seattle, Extended Abstracts 78-1 (1978), p. 906.

Wolf, E.

M. Born, E. Wolf, Principles of Optics (Pergamon, London, 1965).

Young, R. D.

J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.

Appl. Opt. (1)

J. Opt. Soc. Am. (1)

Other (10)

D. A. Swyt, F. Rosberry, D. Nyyssonen, in Proceedings, Kodak Microelectronics Seminar, INTERFACE 1977, Publication G-48 (Eastman Kodak, Rochester, N.Y., 1978).

J. M. Jerke, A. W. Hartman, D. Nyyssonen, R. E. Swing, R. D. Young, W. J. Keery, in Ref. 4, pp. 37–45.

H. L. Kasdan, N. George, Developments in Semiconductor Microlithography, (SPIE, Bellingham, Wash., 1976), Vol. 80, pp. 54–63.
[Crossref]

A. L. Flamholz, R. S. Charsky, in Ref. 3, pp. 120–127.

M. Born, E. Wolf, Principles of Optics (Pergamon, London, 1965).

J. M. Cowley, Diffraction Physics (North-Holland, Amsterdam, 1975).

D. E. Davis, J. K. Hassan, M. R. Wojtaszek, at Electrochemical Society Spring Meeting 1978, Seattle, Extended Abstracts 78-1 (1978), p. 906.

D. Nyyssonen, J. M. Jerke, in Proceedings, International Electronic Devices Meeting, Washington, D.C., 4–6 Dec. 1978, p. 437.

D. Nyyssonen, in Developments in Semiconductor Microlithography III, (SPIE, Bellingham, Wash., 1978), Vol. 135, pp. 115–119.
[Crossref]

D. Nyyssonen, in Developments in Semiconductor Microlithography II (SPIE, Bellingham, Wash., 1977), Vol. 100, pp. 127–134.
[Crossref]

Cited By

OSA participates in Crossref's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (17)

Fig. 1
Fig. 1

Diffraction by the grating test pattern: (a) mask; (b) wafer.

Fig. 2
Fig. 2

Rectangular reflectivity function.

Fig. 3
Fig. 3

Diffracted intensity I(m): (a) for a 10-μm grating in a chrome mask; (b) for a 25-μm grating in photoresist on a uniform SiO2 layer (1000 Å) on Si.

Fig. 4
Fig. 4

Experimental setup for the linewidth measurement on masks.

Fig. 5
Fig. 5

Correlation of laser and SEM measurements for the mebes mask.

Fig. 6
Fig. 6

Correlation of microscopic and SEM measurements for the mebes mask.

Fig. 7
Fig. 7

Correlation of laser, microscopic, and SEM measurements for the photolithographic mask with positive tone.

Fig. 8
Fig. 8

Schematic view of the mask tester: (a) top; (b) front; (c) side.

Fig. 9
Fig. 9

Block diagram of the mask tester.

Fig. 10
Fig. 10

Cross section of structures on IC wafers: (a) after photoresist development; (b) after etching; (c) after photoresist stripping.

Fig. 11
Fig. 11

Test results vs SEM values for twelve different kinds of Si samples with positive patterns on positive photoresist.

Fig. 12
Fig. 12

Test results vs microscope values for a Si wafer with negative patterns on negative photoresist.

Fig. 13
Fig. 13

Diffracted intensity I(m) for a nonrectangular grating (a) before, (b) after gold evaporation.

Fig. 14
Fig. 14

Brewster’s angle incidence on the grating test pattern of a wafer.

Fig. 15
Fig. 15

Test results vs microscope values for a poor sample under. normal (×) and Brewster’s angle (0) incidence.

Fig. 16
Fig. 16

Optical elements of the wafer test set.

Fig. 17
Fig. 17

Mirror arrangement for Brewster’s angle incidence on wafers.

Tables (2)

Tables Icon

Table I Comparison of Nominal, Laser, and SEM Data of a Mask

Tables Icon

Table II Limit of Laser Technique for Very Fine Lines

Equations (8)

Equations on this page are rendered with MathJax. Learn more.

F m = 1 d 0 d r ( x ) exp ( - i 2 π m d x ) d x ,
I ( m ) = U ( m ) 2 F m 2 .
r ( x ) = { r a = r a exp ( i ϕ a ) ; 0 < x < a r b = r b exp ( i ϕ b ) ; a < x < d .
I ( m ) sin 2 ( m π a / d ) m 2 π 2 ( r a 2 + r b 2 - 2 r a r b cos ϕ ) ,
I ( 2 ) I ( 1 ) = cos 2 ( π a / d ) ,
a = d π cos - 1 [ I ( 2 ) I ( 1 ) ] 1 / 2 .
sin φ m = sin φ i + m ( λ / d ) .
tan β = n 1 .

Metrics