JPS63250120A - Alignment correction system - Google Patents

Abstract

PURPOSE:To quickly and highly accurately execute a correction operation to position each prescribed region during a plate-making process according to a global alignment system by a method wherein a distance between marks formed on a plane object according to a previously designed value is measured accurately prior to a stepping shift operation and this measured result is compared with the designed value of the distance between said marks and is operated. CONSTITUTION:After a large-sized substrate 1 has been aligned by using marks 3 for global alignment use, a plate-making operation in a prescribed region of the large- sized substrate 1 is executed during a stepping shift operation. During this process, a distance between marks 2 for distance measurement use in the longitudinal direction and in the transverse direction is measured accurately by using, e.g., a laser interferometer or the like prior to the stepping shift operation (process S1). Then, said measured value is compared with a designed value of the distance between the marks 2 and is operated; the expansion of the large-sized substrate 1 is calculated; an appropriate amount to be corrected for positioning said prescribed region is calculated (process S2). A correction is executed during the stepping shift operation on the basis of said amount to be corrected (process S3). Afterward, said processes S1-S3 are repeated at each stepping shift operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an alignment correction device that accurately measures the vertical and horizontal expansion of a flat object and corrects the positioning.

[Conventional technology]

There are two methods for aligning conventional step-movement type projection exposure apparatuses. They are the die-by-die method and the global alignment method. The former method is a method in which alignment is performed for each chip when performing a photolithography process for LSI, etc., and is considered to be less likely to cause misalignment. The latter method is a method in which alignment is performed once within the wafer, and then plate making is performed using a step-and-repeat method.

In addition, as an alignment method that is an advancement of the die-by-die alignment method, for example, Japanese Patent Application Laid-Open No. 61-258424
There is a method as shown in Publication No. G. This involves aligning a specific shot area on the wafer with the reticle, then measuring and storing the amount of deviation of other shot areas.
The movement of the wafer is controlled based on the stored contents.

[Problem that the invention seeks to solve]

When creating a semiconductor device on a flat object (hereinafter referred to as a substrate), die-by-die alignment requires LS
It is possible to improve the alignment accuracy when manufacturing a large number of devices on a single substrate such as I, but T
PT? & When creating a single device on a large substrate such as a crystal flat display or a contact image sensor, the die-by-die method cannot be used because it is difficult to place marks in the display area. If this is not possible, a global alignment method is used. However, in the global alignment method, as the substrate becomes larger and the process progresses, misalignment of each shot becomes a problem, and there is a problem in that it is difficult to correct the misalignment quickly and accurately.

This invention was made in order to solve the above-mentioned problems, and uses a global alignment method in which a plate-shaped object is first aligned and then the plate-shaped object is moved step by step to make a plate in a predetermined area. It is an object of the present invention to provide an alignment correction device that can automatically perform correction for positioning a predetermined area during step movement in plate making, quickly and with high precision.

Means for Solving Problem c] The alignment correction device according to the present invention adjusts the distance between marks separated from each other by predetermined design values in the vertical and horizontal directions of an object on a flat plate before step movement. Measured to
The measured value and the design value of the distance between marks are compared and calculated to obtain a correction amount for positioning, and positioning correction is performed during step movement based on the correction amount.

[Effect]

In this invention, the distance between marks provided in advance on a flat object according to the design is precisely measured before step movement, and the measurement result is compared with the designed value of the distance between the marks. , the correction amount for positioning during step movement during global alignment is determined based on a single phenomenon of heat leakage of the object on the flat plate or expansion due to the deposited film on the workpiece, so that Positioning correction of a predetermined area of an object can be automatically performed quickly and with high precision.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a large substrate corrected by an alignment correction device according to an embodiment of the present invention;
The figure is a side view thereof. In both figures, 1 is a large board (
2 is a distance measurement mark provided vertically and horizontally on the large substrate 1 and separated from each other by a predetermined setting value, 3 is a mark for global alignment, 4 is a film to be processed, and 5 is a resist It is.

Next, the operation of the apparatus of this embodiment will be explained based on the functional block diagram shown in FIG.

Assume that alignment of the large substrate 1 using the global alignment mark 3 has already been completed.

Next, plate making is performed on a predetermined area of the large substrate 1 while moving in steps. First, before the step movement, the distance between the distance measurement marks 2 in the longitudinal and lateral force directions is measured using a laser interferometer, for example. (Processing Sl
). Then, the measured value and the design value of the distance between the marks 2 are compared, the expansion of the large substrate 1 is calculated, and the optimum correction amount for positioning the predetermined area is calculated (processing S
2). Then, correction is performed during step movement based on the above correction amount (processing S3). Thereafter, the above processes 81 to S3 are repeated for each step movement.

In this way, in the present embodiment device, the distance between the distance measurement marks 2 is measured before step movement, and the correction amount for positioning a predetermined area of the substrate is determined based on the single phenomenon of expansion of the substrate. Since the positioning correction is performed during step movement based on the correction amount, the positioning correction of a predetermined area of a large substrate can be automatically performed quickly and with high precision in plate making using the global alignment method. In an exposure apparatus equipped with such an alignment correction device, exposure work can be performed with good reproducibility and high yield.

Although the present invention is applicable to LSI processes, it is particularly effective for alignment of devices that use large substrates, such as liquid crystal flat displays.

〔Effect of the invention〕

As described above, according to the alignment correction device of the present invention, the distance between the marks separated from each other by predetermined design values in the vertical and horizontal directions of a flat object is measured before step movement, and The measured value and the design value of the distance between marks are compared and calculated to find the correction amount for positioning, and the positioning correction is performed during step movement based on the correction amount, so plate making using the global alignment method is possible. This has the advantage that the positioning correction of each predetermined area can be automatically and quickly (and highly accurately performed).

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a large substrate corrected by an alignment correction device according to an embodiment of the present invention, FIG. 2 is a side view of the large substrate, and FIG. 3 is an alignment correction device according to an embodiment of the invention. FIG. In the figure, 1 is a large board, 2 is a distance measurement mark, and 3 is a large board.
is the mark for global alignment, 4 is the film to be processed, 5 is
is a resist. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In plate making using a global alignment method in which a plate-shaped object is first aligned and then the plate-shaped object is moved in steps while plate-making is carried out in a predetermined area.
The alignment correction device performs correction for positioning the predetermined area, and the alignment correction device moves the distance between marks separated from each other by a predetermined design value in the vertical and horizontal directions of the flat object in each step. a measuring means for measuring before each step; a calculating means for calculating a correction amount for positioning correction by comparing and calculating the measured value by the measuring means and the design value of the distance between the marks; An alignment correction device comprising: correction means for correcting the positioning of the predetermined area based on the correction amount.