JPS5821824A - Wafer alignment method - Google Patents

Abstract

PURPOSE:To allow the array of a mask to be highly reproducibly positioned at the same place in the first exposure, by a method wherein before the mask is fixed, a mask chuck is returned to a neutral position by employing a return mark provided thereto. CONSTITUTION:A mask 41 has a pattern array 42, and alignment marks 43 are provided at predetermined positions corresponding to the coordinates of the pattern array 42. A mask chuck 44 is provided with a return mark 45 for returning the mask chuck 44 to a neutral position before fixing the mask 41, together with alignment targets 46, the return mark 45 and the alignment targets 46 being disposed at positions different from each other. To carry out the first lithography, the chuck 44 is returned to the neutral position by employing the return mark 45 provided thereto. Then, the target 46 provided to the chuck 44 and the marks 43 are aligned with each other by moving the mark 41, and the mask 41 is fixed to the chuck 44.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a wafer alignment method in the manufacture of semiconductor devices.

In the conventional wafer alignment method, a mask patterned on a glass plate is loaded into a holder or directly set on a mask chuck of an aligner. However, in this conventional method, as shown in FIG. 1, when the mask 11 is loaded onto the chuck [2, the funnel 9 error 16° in the X direction, the funnel 9 error 15 in the X direction, and the crystal axis are centered on the wafer. There is a problem in that a rotation error 14 occurs with respect to the determined orientation flat. In addition, the mask position fixing bin and the detection unit 17 are also located at a unique position from the mounting rift K, so that the iJ? Turn a 1/i 13'f! : It was difficult to position with good reproducibility. Furthermore, as shown in FIG. 2, the mask 21)
9th turn A1/I22 is due to rotational error 23. made during mask manufacturing. X position error? I have it. Therefore, the first
There was a problem in that the wafers during the second four-dimensional process were placed at different positions for each lot, as illustrated in FIG. 3, 1C.

In this invention, the target of the mask and the alignment target provided on the mask chuck are aligned to completely fix the mask to the mask chuck, and the mask chuck is moved to the neutral position before fixing the mask by moving around the return mark provided on the mask chuck. By returning to the position, the A1/A position of the mask is brought to the same position with good reproducibility during the first exposure, thereby providing a 7ζwafer alignment method 1
- 75 degrees or less, one embodiment of the present invention will be described with full reference to FIG.

According to Figure 4, it is %41 & em mask, and -mask 41 (α)! There is a turn A/I 42, this is,
An alignment mark 43 is provided at a predetermined position corresponding to the coordinates. 44 years old is a mask chuck.

Before fixing the mask 41, this chuck 44 has a V mark 4 indicating that the mask should be returned to the neutral position.
5 and the alignment target 46 are different from each other f-
, located at the same location. Note that 47 (1 alignment scope %) 48 is a semi-transparent mirror that passes projection light from a position alignment method light source (not shown).

In this ritual process, when performing the first IJ sographie, the mask chuck 44 is returned to the neutral position using the return mark 45 provided on the mask chuck 44, and then Move the mask 41 to align the alignment dots 46 and the alignment marks 43 of the mask 4I, and use an appropriate method such as vacuum suction to attach the mask chuck 441c to the mask 41.
to be fixed.

Furthermore, the mask and wafer chuck are positioned so that the alignment mark 43 and the alignment mark 43 of the wafer chuck (not shown) on which the wafer is mounted are closely aligned. , 1st P ;
't'l-, please note the above mask and wear 1.
It is preferable that the applicant of the present invention first set out the positioning with the chin and use the method described in No. 1F!'M No. 95920-, published in 1973.

In addition, in this invention, the alignment mark 43 is not necessarily provided on the mask 4, and the alignment mark 43 is not necessarily provided on the mask 4, but the alignment mark 43 is targeted at the scribe line of Mars.

As explained above, according to the method of the present invention, before fixing the mask, the mask chuck is returned to the neutral position using the return/station side mark provided thereon.
C, the mask chuck can be returned with high precision and good reproducibility, and by combining the mask alignment mark and scribe line machining with the previous mask chuck's alignment mark. , Attach the mask to the mask chuck and, uh, L sea urchin! -Therefore, these two systems; It becomes possible to control the VC control and therefore the alignment between the aligners)? I'm glad that the positions of Tersoor 1 and f will be unified.
Ara 1'su()) Mutual Shii 1 law is the same as above, and
The seedlings that can be used to shorten the ``d9 ft1j'' of the 2nd JJ descending array member 91) have been found, and especially when the auto-alignment method is used, the advantage of making the 2' loops the same can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the position in which the mask is rotated by the conventional wafer alignment method. FIG. 2 is a diagram showing the A' turn one noise error of the mask. FIG. 3 is a diagram showing errors in a pattern array on a wafer, and FIG. 4 is an explanatory diagram of an evaporative alignment method according to an embodiment of the present invention. 41...Mask, 42...ノ43'-7"71//
(, 43... Alignment mark, 44... Mask chuck. 45... Return mark, 46... Alignment tart.

Claims (1)

[Claims] In an aligner for manufacturing semiconductor devices. The mask has a target such as an alignment mark or a scribe line at a predetermined position corresponding to the turnor 1/a, and an alignment target is provided on the mask chuck at a position where the eye ffl'e is aligned, and the target is A wafer alignment method characterized in that the mask is attached to the mask chuck by adjusting the mask chuck, and the mask chuck is returned to a neutral position using a return mark provided on the mask chuck before fixing the mask.