JPH04277611A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable further micronization by improving the precision of overlapping over the whole region of a semiconductor device. CONSTITUTION:A pattern of indices 2 is set on an exposure mask before patterning for the first substrate working, and exposure is made simultaneously with an LSI pattern 1. Before mask patterns for the second and after substrate working and ion implantation are exposed, a strain of the exposure region is measured and corrected based on the indices 2 formed in the first working.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device which includes a plurality of transfer steps.

0002

2. Description of the Related Art When forming a semiconductor device, pattern transfer is performed several to ten times. Heat treatment and film formation are performed during this pattern transfer process, and distortion occurs in the semiconductor substrate during this process. Conventionally, in order to remove this distortion,
The distortion of the entire board is measured and corrected.

[0003]Furthermore, in recent years, as the degree of integration of LSI has improved, the chip area has increased. In response to this, semiconductor exposure equipment manufacturers are supplying products that can transfer patterns over large areas. Distortion within the transfer area is a problem when transferring a large area, but conventionally this has been addressed by improving the positioning accuracy of the transfer position and absorbing the tilt of the transfer area.

0004

However, with the miniaturization of semiconductor devices and the increase in the area of transfer patterns, distortion in the plane direction within the area that can be transferred at one time has become impossible to ignore.

SUMMARY OF THE INVENTION An object of the present invention is to provide a means for correcting distortion in the plane direction of an area that can be transferred at one time and improving the degree of integration of a chip.

[0006]

[Means for Solving the Problems] A method for manufacturing a semiconductor device according to the present invention provides an index on the outer periphery of a region that can be transferred in one step, and uses the index after the completion of one transfer step to prevent distortion of the region. The present invention is characterized by having a step of measuring the magnification and correcting the magnification in reduction transfer.

[0007]

[Operation] By using the above-mentioned present invention, it is possible to measure and correct the distortion caused by the first step in the area that can be transferred in the first step, so for the second and subsequent steps, it is possible to measure the position of the previously formed index. This makes it possible to read changes in the size of each transfer area, correct the magnification in reduction transfer, and reduce pattern overlay errors at the center of each transfer area and at the edges of the area.

[0008]

[Example] The present invention will be explained in detail below based on an example.

FIG. 1 shows a plan view of an embodiment of the present invention.
FIG. 2 shows a plan view of another embodiment of the invention. 1 is LSI
Pattern, 2 indicates index. In FIG. 1, when one LSI pattern 1 is transferred in one transfer, the index 2
are provided at the four corners of the LSI pattern 1. Also,
In FIG. 2, when four LSI patterns 1 and indicators 2 are transferred in one transfer, the indicators 2 are provided at the four corners of the outer periphery of the entire area of the four LSI patterns 1.

Next, the manufacturing process will be explained.

When performing patterning for the first substrate processing, a pattern of index 2 is set on the transfer mask, and transferred simultaneously with LSI pattern 1. At this time, it is desirable that the indicators 2 be placed at the four corners of the required LSI 1.

From the second time onwards, after removing the distortion of the entire substrate using the conventional technique, when transferring the mask pattern for substrate processing and ion implantation, transfer is performed based on the index 2 formed during the first processing. Measure the expansion and contraction of the area. Measurement methods include: ■ A method in which a laser beam is incident obliquely on the substrate, the reflected light level from an index 2 formed on the substrate is converted into a signal, and the stage position where the substrate is being adsorbed at that time is read, and ■ A monitor microscope. A method is used in which the index 2 is aligned with the measurement position on the apparatus side (manual correction), and the stage position at which the substrate is being sucked at that time is read.

After measuring the distortion of the transfer area as described above,
After correcting the magnification in reduction transfer, pattern transfer is performed, and the above steps are repeated to form an LSI. As a correction method, ■ a method using a variable magnification lens group;
(2) A method of changing the refractive index by adjusting the pressure of gas (for example, air) between lenses is performed.

[0014]

[Effects of the Invention] As explained in detail above, by using the present invention, it is possible to improve the overlay accuracy over the entire chip area, which is increasing, and further enable miniaturization. .

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a plan view of another embodiment of the invention.

[Explanation of symbols]

1 LSI pattern 2 Indicators

Claims (1)

[Claims] 1. In a method for manufacturing a semiconductor device having a plurality of transfer steps, an index is provided at the outer periphery of a region that can be transferred in one step, and after one transfer step is completed, the region is 1. A method of manufacturing a semiconductor device, comprising a step of measuring distortion of the image and correcting magnification in reduction transfer.