KR20000074366A - Mask &reticle for alignment accuracy measurement - Google Patents

Abstract

PURPOSE: A disc for measuring an alignment accuracy is provided to compatibly use different kinds of alignment exposing elements in each lithography step for manufacturing a certain semiconductor element. CONSTITUTION: In a disc for measuring an alignment accuracy, unit blocks(42) composed of 8x4 chips, in which an autoalign key for CANON stepper, a wafer global alignment mark for NIKON stepper, a horizontal alignment mark for UT stepper, a prealign key for CANON stepper, and a laser scan alignment mark for NIKON stepper are drawn in a scribe line, are disposed correspondingly to a whole wafer, and a block(42a) for perkin elmer and UT stepper composed of autoalign key(4) for perkin elmer and an optical alignment target(7) of the UT stepper added further to the unit block is disposed in the centers of uppermost and lowermost parts of the wafer.

Description

Disc for measuring accuracy of accuracy {Mask & reticle for alignment accuracy measurement}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a disc for measuring the degree of alignment of a semiconductor device, which makes it possible to use heterogeneous alignment exposures interchangeably.

Lithography processes in semiconductor manufacturing process technology include the steps of applying photoresist on a wafer, exposing the photoresist to light using ultraviolet wavelengths, and developing the reacted photoresist. (develop) to proceed to form a pattern. Alignment exposure equipment is used to react light with photoresist applied on the wafer. The projection type perkin elmer aligner and the step and refit type according to the configuration and exposure method of each facility. Canon stepper and Nikon stepper, which use an 5: 1 reduction lens as a repeat type, and Uti Stepper, which uses a 1: 1 reduction lens as a step and refit type. UT stepper).

Alignment exposure machines used in the lithography process have high resolution, high speed, alignment accuracy, which are inherent in each facility, and the pattern size and interlayer overlap margin required for the design of the product. Although it has been separately applied in consideration of overlap margin, etc., in recent years, in terms of cost reduction and quality improvement of products, the resolution capability of each layer and the degree of misalignment are selected based on the degree of heterogeneous alignment exposure period. (Iii) Compatibility progress is required.

As a result, MIX & MATCH technology has been developed to enable interchangeability between alignment exposure machines, and among the current products, among the projection type and step and refit type alignment exposure machines and step and refit type alignment exposure machines, the 5: Compatibility has been achieved between alignment exposure units using one reduction lens and alignment exposure units using 1: 1 reduction lens. However, in this case, misalignment may be caused by differences in lens distortion, magnification, skew, etc., which may occur between heterogeneous alignment exposure machines, resulting in compatibility progress problems. Therefore, a review of the alignment degree measurement and management method, which is one of the important equipment management items of the alignment exposure machine, is required.

Fig. 1 is a plan view showing a conventional mask used in a projection type alignment exposure apparatus, in which reference numeral “10” denotes a mask, “12” a chip, and “14” an autoalign key. ). Using the mask of FIG. 1, the chips of the entire wafer can be exposed at once with one shot.

FIG. 2 is a plan view of a reticle used for Canon stepper and Nikon stepper, which is an exposure method using a 5: 1 reduction lens as a step-and-refit type alignment exposure machine, and reference numeral 20 denotes a reticle. Is the alignment key for Canon stepper, "24" is the prealign key for Canon stepper, "26" is the Wafer Global Alignment Mark for Nikon stepper, and "28" is Nikon A laser scan alignment mark for steppers is shown. Using the reticle of Fig. 2, one shot can expose 5x5 chips at a time.

3 is a plan view of a reticle for use in a Uti sputter, which is an exposure method using a 1: 1 reduction lens with a step-and-refit type alignment exposure apparatus, where reference numeral 30 denotes a reticle, and reference numeral 32 denotes a horizontal alignment mark ( Horizental Alignment Mark, "34" stands for Optical Alignment Target, and the three layouts drawn at the bottom of the reticle of each of the six independent layouts are layouts that are not actually used for disc validation. Of the three layouts, the left (field 1) is the layout used for actual exposure, the middle (field 2) is the layout used for alignment, and the right (field 3) is optionally used as an option. Using the reticle of FIG. 3, one shot can expose twice the 5 × 5 chips at once.

SUMMARY OF THE INVENTION An object of the present invention is to provide a disc for measuring the degree of alignment of a semiconductor device which makes it possible to use heterogeneous alignment exposures interchangeably.

Fig. 1 is a plan view showing a conventional mask used for a projection type alignment exposure machine.

Fig. 2 is a plan view of a reticle used for Canon stepper and Nikon stepper, which are exposure methods using a 5: 1 reduction lens as a step-and-refit type alignment exposure machine.

3 is a plan view of a reticle used for a uti stepper, which is an exposure method using a 1: 1 reduction lens as a step-and-refit type alignment exposure machine.

Fig. 4 is a plan view showing a mask used for a projection type alignment exposure apparatus that enables compatibility of heterogeneous alignment exposure periods.

Fig. 5 is a plan view of a reticle used in a 5 x step and refit type alignment exposure apparatus that enables compatibility of heterogeneous alignment exposure periods.

Fig. 6 is a plan view of a reticle for use with a 1 × step and refit type alignment exposure apparatus that enables compatibility of heterogeneous alignment exposure periods.

In order to achieve the above object, a disc for measuring alignment accuracy used in a projection type alignment exposure apparatus of a semiconductor device according to the present invention includes an autoalign key for Canon stepper, a wafer global alignment mark for Nikon stepper, and a tee stepper. Unit blocks consisting of 8 × 4 chips drawn with horizontal alignment marks, pre-align key for Canon stepper, and laser scan alignment mark for Nikon stepper are placed on the scribe line so as to correspond to the entire wafer, Perkin Elmer and Uty stepper blocks further comprising an Elmer auto-align key and a Uty stepper optical alignment target are arranged so as to correspond to the top center and bottom center of the wafer.

In order to achieve the above object, the disc for alignment accuracy measurement used in the 5 × step-and-refit type alignment exposure apparatus according to the present invention includes an autoalign key for Canon stepper, a wafer global alignment mark for Nikon stepper, and a uti stepper. A chip portion consisting of 4 x 4 chips drawn on the scribe line with a horizontal alignment mark for the Canon, a pre-align key for the Canon stepper, a laser scan alignment mark for the Nikon stepper, and an auto-alignment for the Perkin under the chip. And a block for Perkin Elmer and a Uty stepper on which an optical alignment target for a key and a tee stepper is drawn.

In order to achieve the above object, the disc for alignment accuracy measurement used in an 1 × step-and-refit type alignment exposure machine includes an auto alignment key for Canon stepper, a wafer global alignment mark for Nikon stepper, and a horizontal alignment mark for Uti stepper. A field 1 consisting of 8 × 4 chips drawn on a scribe line with a pre-align key for a Canon stepper, a laser scan alignment mark for a Nikon stepper, and a perk where the upper left portion of the left 4 × 4 part of the field 1 corresponds. And a field 2 on which an auto alignment key for elmer and an optical alignment target for a stepper are drawn.

Therefore, according to the present invention, in the fabrication of any semiconductor device, it is possible to use a different alignment exposure device for each lithography process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape and the like of the elements in the drawings are exaggerated to emphasize a more clear description, and the elements denoted by the same reference numerals in the drawings means the same elements.

The present invention is a reticle & mask for overlay measurment between heterogeneous exposure exposure apparatus to enable the pre-management of misalignment errors occurring when the heterogeneous alignment exposure equipment used in the alignment exposure operation is compatible. Describes In order to manufacture the disc described above it goes through the steps described below.

Stage 1; Facility capability analysis between alignment exposure machines

Through the analysis of resolution capability, alignment accuracy, and facility management capability by alignment exposure equipment, the auto-align key is selected and the type of vernier key for misalign measurement is determined.

Step 2; Analysis of Disc Manufacturing Method by Alignment Exposure Machine

(1) Understanding the original frame

The discs are divided into 1: 1 6-inch masks for Perkin Elmer Aligners, 5: 1 5-inch reticles for Canon and Nikon steppers, and 1: 1 5-inch reticles for Uti steppers, depending on the type of aligner. Each frame is composed of an image field and a chip array in consideration of the lens size.

(2) Understanding Auto Alignment Keys or Marks by Alignment Exposure

The auto-align key used for each of the alignment exposure units is an auto-align key for photo diode recognition by Perkin Elmer Aligner, a laser beam scan (LBS) mark as an auto-align key used in Canon steppers, and a pre-align line. TV (TV) key to recognize pattern image using He-cd / He-Ne laser as key, wafer global alignment (WGA) mark as auto-align key used in Nikon stepper, laser as pre-align key There are a scan alignment (LSA) mark, a horizontal alignment mark (HAM's) as an auto alignment key used in the utility stepper, and an optical alignment target (OAT) as a free alignment key.

Each auto-align key used for each equipment has factors that affect alignment accuracy, such as shape, size, and polarity, and should be considered when configuring the layout of the original.

Step 3; Analysis of alignment accuracy measurement patterns

Vernier keys are used to measure the alignment accuracy of heterogeneous exposure exposure periods. Accurate positioning is required to facilitate the analysis of alignment defects occurring in each facility. The vernier key is positioned in all directions and centers of the field constituting the reticle to match the distortion and misalignment of the lens and configures the chip of the mask to match it.

Step 4; Functional pattern insertion analysis

Function patterns such as the resolution capability verification pattern for each facility should be inserted to increase utilization.

4 to 6 are plan views illustrating an original plate for measuring the degree of alignment that enables compatible heterogeneous exposure periods completed through the above-described steps.

Fig. 4 is a plan view showing a mask used in a projection type alignment exposure apparatus which enables compatibility of heterogeneous alignment exposure periods, in which a reference numeral “40” is a mask and “42” is a unit block composed of 8 × 4 chips. "42a" is a Perkin Elmer and Uty stepper block having the automatic alignment key for Perkin Elmer and the optical alignment target for the Uty stepper among the unit blocks, and ④ is the autoalign key for the Perkin Elmer, Represents an optical alignment target for the utility stepper. Using the mask of Fig. 4, a single shot can expose the chips of the entire wafer at once.

The unit blocks 42 are laid out in three lines in the first line, five in the second to ninth lines, and finally three in the ten lines, and the second block 42a of the first and tenth lines. Equipped with an Auto Align key for Perkin Elmer and an optical alignment target for Uti Stepper. Each unit block 42 is composed of 8 × 4 chips and various keys or marks formed on a striation line between the chips, and these various keys or marks are described in the reticle of FIG. 5 or 6 described later. Has the same shape as. Further, the Perkin Elmer and Uti stepper blocks 42a have the same shape as the field 2 of the reticle of FIG. 6.

That is, the mask of FIG. 4 includes the auto alignment key ① for Canon stepper, the wafer global alignment mark ② for Nikon stepper, the horizontal alignment mark ③ for Uty stepper, and the prealignment for Canon stepper. The unit blocks 42 made up of the key and the Nikon stepper laser scan alignment mark ⑥ on the scribe line are arranged so as to correspond to the entire wafer, and the unit blocks 42 are arranged on the unit block 42. The Perkin Elmer and Uty Stepper blocks 42a, which further include the Perkin Elmer Auto Alignment Key (4) and the Uty Stepper Optical Alignment Target (7), are disposed so as to correspond to the top center and bottom center of the wafer. .

Fig. 5 is a plan view of a reticle for use in a 5 × step and refit type alignment exposure apparatus which enables compatibility of heterogeneous alignment exposure periods, in which reference numeral “50” denotes a reticle and ① denotes an auto alignment key for a Canon stepper, ② denotes a wafer global alignment mark for Nikon stepper, ③ denotes a horizontal alignment mark for Uti stepper, ⑤ denotes a pre-align key for Canon stepper, and ⑥ denotes a laser scan alignment mark for Nikon stepper. Using the reticle of FIG. 5, 4 × 4 chips can be exposed at once with one shot.

The reticle of FIG. 5 is an auto alignment key ① for Nikon stepper, a global alignment mark mark ② for Nikon stepper, a horizontal alignment mark mark ③ for Uti stepper, and a prealign key for Canon stepper ( ⑤) and a unit block 52 of 4 × 4 chips with a laser scan alignment mark (⑥) for the Nikon stepper drawn on the stripes line between the chips, an autoalign key (④) for the Perkin Elmer, and an optical for the stepty stepper. It is divided into the perkin elmer and the tee stepper block 54 in which the alignment target (⑦) is drawn.

Fig. 6 is a plan view of a reticle for use in a 1 × step and refit type alignment exposure apparatus that enables compatibility of heterogeneous alignment exposure periods, in which only the layout 60 of field 2 is drawn. The field 1 may be configured in the same manner as the corresponding part on the right side after removing the left perkin elmer autoalignment key (4) and the utility stepper optical alignment target (7) from the left field 2 (60). The layout of field 1 is similar to the one in which the reticle of FIG. 5 is drawn in succession. In FIG. 6, one field is composed of 8 × 4 chips.

That is, the reticle of FIG. 6 includes the auto alignment key ① for Canon stepper, the wafer global alignment mark ② for Nikon stepper, the horizontal alignment mark ③ for Uti stepper, and the prealign key for Canon stepper. (5) and field scan consisting of 8 x 4 chips drawn on the scribe line with a laser scan alignment mark (6) for Nikon stepper, and the perforated Elmer Auto at the top of the left 4 x 4 part of the field 1 It includes the field 2 on which the alignment key (4) and the optical alignment target (7) for the utility stepper are drawn. At this time, the field 3 has the same layout as the field 1.

Each of the keys or marks described with reference to FIGS. 4 to 6 is uniquely designated according to the alignment exposure model, and cannot be arbitrarily changed by the user. For example, in the Canon stepper, a vertical line is designated by the auto alignment key as shown in (1) of FIG. 5, and in the uty stepper, the horizontal alignment mark is designated as a horizontal line as (3) in FIG.

Hereinafter, in the first lithography process, a projection type alignment exposure machine is used, in the second lithography process, a 5 × step and refit type alignment exposure machine is used, and in the third lithography process, a projection type alignment exposure machine is used. The lithography process describes the use of the aforementioned discs in any semiconductor device fabrication process using a 1 × step and refit type alignment exposure machine.

First, in the first lithography step, exposure is performed using the mask of FIG. 4 to transfer the layout drawn in FIG. 4 on the wafer as it is. Next, in the second lithography process, exposure is performed using the reticle of FIG. 5, in which case the chip portion 52 of FIG. 5 is exposed to the portions except for the Perkin Elmer and Uti stepper blocks 42a of FIG. 4. The alignment accuracy is measured using a key or a mark of), and in the Perkin Elmer and Uti Stepper block 42a, the Perkin Elmer and Uti Stepper block 54 and the chip portion 52 of FIG. Measure the accuracy of alignment. At this time, since all the keys or marks drawn on the chip portion of FIG. 5 are drawn in the unit block 42 of FIG. 4, there is no problem in alignment.

Subsequently, in the third lithography step, exposure is performed using the mask of FIG. 4, at which time, the alignment accuracy may be measured using the Perkin Elmer and Uti stepper blocks 42a. Lastly, in the fourth lithography process, exposure is performed using the reticle of FIG. 6, in which case exposure to portions other than the Perkin Elmer and Uti stepper blocks 42a of FIG. 4 is performed. The alignment accuracy is measured using a layout, and the alignment accuracy is measured using the layout of field 2 of FIG. 6 in the Perkin Elmer and Uti stepper block 42a.

According to the original plate for measuring the accuracy of alignment of a semiconductor device which enables heterogeneous alignment exposure period compatibility according to the present invention, it is possible to use a different alignment exposure device for each lithography process in manufacturing any semiconductor device.

Claims (3)

8 × 4 with auto-align key for Canon stepper, wafer global alignment mark for Nikon stepper, horizontal alignment mark for Uti stepper, pre-align key for Canon stepper, and laser scan alignment mark for Nikon stepper Unit blocks consisting of four chips are arranged to correspond to the entire wafer, Heterogeneous alignment, characterized in that the Perkin Elmer and Uty stepper blocks further added to the unit block to the automatic alignment key for Perkin Elmer and the optical alignment target for the Uty stepper are arranged to correspond to the center of the top and bottom of the wafer A disc for measuring alignment accuracy used in projection type alignment exposure machines that enables compatibility of exposure periods. 4 x 4 drawn on the scribe line with the Canon alignment stepper, the Nikon stepper wafer global alignment mark, the uti stepper horizontal alignment mark, the Canon stepper prealignment key, and the Nikon stepper laser scan alignment mark A chip portion consisting of four chips, 5 x step-and-narrow for compatibility with different alignment exposure periods, characterized by a perkin elmer and a tee stepper block having an automatic alignment key for the perkin elmer and an optical alignment target for the tee stepper under the chip portion. A disc for measuring alignment accuracy used in refit type alignment exposure machines. 8 × 4 with auto-align key for Canon stepper, wafer global alignment mark for Nikon stepper, horizontal alignment mark for Uti stepper, pre-align key for Canon stepper, and laser scan alignment mark for Nikon stepper Field 1 consisting of four chips, 1 to enable compatibility of the heterogeneous alignment exposure periods, wherein the field 2 having the automatic alignment key for the Perkin elmer and the optical alignment target for the tee stepper is formed at a position corresponding to the upper left portion of the left 4 × 4 part of the field 1. × A disc for alignment accuracy measurement used in staff-and-refit type alignment exposure machines.