UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 1

UT524A

Reticle Features 19-25-05430 Rev. A

Copyright © September 2006

Ultratech, Inc.

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 2

Introduction

The UT524A test reticle is a 6”X6”X0.250” reticle used on the AP300I/Unity Platform

steppers for calibration and stepper set-up purposes. It is designed to support the a 34x26 mm field

size. Set-up of the MVS and AFAS systems is also supported.

Specifications:

SUBSTRATE : 6 X 6 X 0.250” 2 µm flat quartz

FILM : 3.0 OD Anti-reflective Chrome

CD SPECIFICATION:

The 2.0um lines are specified to a tolerance of +/- 0.05um; Mean to Nominal

RESOLUTION: 1.0µm lines must be resolved in both fields.

ARRAY PLACEMENT:

(Measured chrome-side up from the lower-left corner of the mask)

1 location in (X) to be 12.00 ± 0.50 mm

2 locations in (Y) to be 102.530 ± 0.50 mm

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 3

UT524A Reticle View

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 4

Field 1 is comprised of the following:

Field 1 is mostly dark (chrome) field 2mm x 2 mm cells - arrayed in a 34 X 26 mm field size

Short-step focus patterns, both dark and clear field, ranging from 1.0 to 6.0 microns;

contacts have been included in these patterns.

Verniers designed for overlay tests with alignment. Also included are box-in-box

structures for integration with automatic inspection techniques. See drawing on page

9.

Projection AFAS targets have been added. There are two types, one at 6 locations in the

field, and one at 2 locations per field.

A 600x600um clear window for AFAS calibration has been added centered at –3.0mm

in X and –8.60mm in Y from the center of baseline.

OAT - 2X2 mm at X: -13.0mm, Y: -10.6mm from image reference point (0,0)

Labels for MVS windows indicating X location of window referencing field center

Large coordinates at top of field for setup

Scribe border on three sides

Blind step box in frame structures along the edges of the field with labels (5

horizontally and 5 vertically). Look for the vertical blindstep boxes near the (Y) –1; -5;

-11, -17, and –21 cells. Look for the horizontal blindstep boxes near the (X) –16, -7, 1,

7, and 17 cells. To use these features, the field step size MUST be 34x26mm.

There are three types of MVS windows. They are:

Windows with checkerboard-type MVS keys at +/- 11.5mm

Windows with std-type MVS keys at +/- 9.5 and +/- 15.5mm

Windows without keys (blank) at +/- 13.5mm (used for calibration)

All MVS keys within MVS windows are centered at 3.055mm above the baseline

MVS self-calibration target sets are at 9 locations as follows: They are in columns

X-15, X1, and X15, and in Rows Y-1, Y-11, and Y-19.

The blindstep patterns are updated to provide the user to check blindstep accuracy

using different methods: MVS; Optical verniers, and auto-metrology box-in-frames.

A 0.30mm x 4.0mm clear bar for auto-metrology tool global capture has been added at

column X 3 and across rows Y –9 and Y –11. See drawing on page 9.

Vertical and horizontal rulers added as an aid for centering the wafer on the chuck. The

horizontal scale is on the baseline and centered at +10.0mm in X from field center, and

the vertical scale is centered at 10.0mm below the baseline and at the field center in X.

See the drawing on page 12.

A set of 4 MVS targets is placed directly under each MVS window, with the upper

targets –600um below the baseline, and the lower target located at –750um from the

baseline. See the drawing on page 8.

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 5

Field 1 (continued):

Fifteen cells, 2mm x 2mm, containing lines and contacts ranging from 8 to 100

microns. See drawing on page 10.

Special 2x2mm cells with short-step focus structures at X-11, Y-5; X-11, Y-25;

X-1,Y-13; X11,Y-5, and X11, Y-25. See drawing on page 12.

Field 2 is comprised of the following:

Field 2 is a mostly clear field version of Field 1 2mm X 2 mm cells - arrayed in a 34 X 26 mm field size

Short-step focus patterns, both dark and clear field, ranging from 1.0 to 6.0 microns;

contacts have been included in these patterns.

Verniers designed for overlay tests with alignment. Also included are box-in-box

structures for integration with automatic inspection techniques.

Projection AFAS targets have been added. There are two types, one at 6 locations in the

field, and one at 2 locations per field.

OAT - 2X2 mm at X: -13.0mm, Y: -10.6mm from image reference point (0,0)

Labels for MVS windows indicating location of window referencing field center

Large coordinates at top of field for WAS setup

There are three types of MVS windows. They are:

Windows with checkerboard-type MVS keys at +/- 11.5mm

Windows with std-type MVS keys at +/- 9.5mm and +/- 15.5

Windows without keys (blank) at +/- 13.5mm (used for calibration)

All MVS keys within MVS windows are centered at 3.055mm above the baseline

MVS self-calibration target sets are at 9 locations as follows: They are in columns

X-15, X1, and X15, and in Rows Y-1, Y-11, and Y-19.

Vertical and horizontal rulers added as an aid for centering the wafer on the chuck. The

horizontal scale is on the baseline and centered at +10.0mm in X from field center, and

the vertical scale is centered at 10.0mm below the baseline and at the field center in X.

See the drawing on page 12.

A set of MVS Off-axis targets are at ± 19.5mm in X and –600um in Y.

A set of 4 MVS targets is placed directly under each MVS window, with the upper

targets –600um below the baseline, and the lower target located at –750um from the

baseline. See the drawing on page 8.

Fifteen cells, 2mm x 2mm, containing lines and contacts ranging from 8 to 100

microns. See drawing on page 10.

Special 2x2mm cells with short-step focus structures at X-11, Y-5; X-11, Y-25;

X-1,Y-13; X11,Y-5, and X11, Y-25. See drawing on page 12.

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 6

UT524A Field 1 View

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 7

UT524A Field 2 View

Short-step Focus cells

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 8

Short-step Focus cells

MVS target sets

-0.750mm

-0.600mm

0.140mm 0.140mm

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 9

View after 2 exposures with for alignment testing

ID/Logo’s created by two

exposures with 300um Y

shift at 2nd

exposure

coarse verniers (0.25um)

Box-in-frame

fine verniers (0.10 & 0.20um)

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 10

2x2 Cell – 8.0um to 100um (19 placements per field)

AFAS Targets (2 types)

Triple-line

design- 2

locations per

field

Single-line

design- 6

locations per

field

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 11

Detail view of MVS windows and targets- top left of field 1

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UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 12

Scale used to aid in centering wafer on chuck

Reads to +/- 2.0mm in 0.050mm (50 micron) increments

View of special SSF Focus cell

Example of SSF focus pattern

UT524A Feature Descr. PN 19-25-05430 Rev. A, ECO 14507 13

Blindstep Structures - Overlayed

Verniers- 0.20um increments- 0 to 2.0um range

Center target and top label

printed from left and top side

of field

4 outer targets and bottom

label printed from right

and bottom side of field

Blindstepped MVS targets, measurable by

MVS system

Outer frame printed by left

and bottom side of field

Inner box printed by right

and top side of field