JPH02198128A - Method of recording and reading identification information of semiconductor wafer - Google Patents

Abstract

PURPOSE:To enable recording and reading with a simple optical apparatus by using a one-dimensional bar code as identification information to record into wafers of the raw material of a semiconductor integrated circuit. CONSTITUTION:A wafer 1 is mounted on a mount 1a, the image of a slit 4b is projected to positions corresponding to each of the bars of a bar code 3 in a region near the OF of the wafer 1 and exposed to a light one after another with a projection aligner 4 comprising a light source 4a, the slit 4b, and an image formation lens 4c, and development and processing with an etching apparatus are performed to record the bar code 3. In reading, the bar code 3 is illuminated with an illuminator 7 and the image is formed on a line sensor 8b through an objective lens 8a. The line sensor 8b is formed from a one-dimensional CCD and the output signal thereof is decoded by the use of a binary-coding circuit 9 and a signal processing circuit 10. The bit configuration of the bar code 3 includes manufacture lot numbers and numbers of each wafer only, therefore, a simple apparatus can be used. Thereby the identification information of the semiconductor wafers can be recorded and read at a low cost and control of the wafers in an IC plant can be rationalized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for recording and reading ID information on a wafer of semiconductor IC material.

[Prior Art] ICs often used in electronic devices are manufactured from wafers of silicon or the like. In the manufacture of ICs, the surface of the wafer as a raw material is inspected, and the IC pattern, which is etched through projection exposure on the wafer λ, is inspected at each stage. At wafer manufacturing factories, no identification (ID) information such as serial numbers is recorded for individual wafers, but at IC manufacturing factories that receive wafers, ID information for each wafer is recorded in advance. If there is, it will be convenient for product management. Recently, I
As the amount of C produced and, therefore, the amount of wafers used is increasing, the need for wafer number management is also increasing.

Figure 3 explains the format of conventional ID information for wafers and its recording method.
Since there is an unused area in C, alphanumeric character pattern 2 is recorded in this area.

Recording methods include a method of directly drawing a character pattern on the wafer by projecting a laser beam and thermal action, or a method of exposing a mask of the character pattern using a projection method, developing and etching it, and recording it as IDVt information. It is being done. To read it, use two devices such as a COD camera.
A method is being used in which a dimensional sensor takes an image and character patterns are recognized through image processing.

[Problems to be solved] The conventional ID information recording method described above requires a fairly complicated device to draw the character pattern, and the reading method is two-dimensional image processing, so it requires hardware, Both software are complex and large in scale, and this
The cost of providing each C manufacturing device is not small. Therefore, a simpler and more economical recording/reading method is desired.

This invention was made in view of the above, and aims to provide a system that uses a simple one-dimensional barcode as ID information and records/reads it with a simple optical device.

[Means for Solving the Problems] This invention provides an OF
A bar code representing ID information used for wafer management is recorded by a projection exposure means provided in the recording device in an area close to the IC manufacturing or testing device. It is read by an optical reading means.

The projection exposure device of the projection exposure means described above transmits a light beam from a light source through a slit onto the wafer, forms an image of the slit on the wafer using an imaging lens, and places the slit at the array position of the bar code. The image is moved step by step and stopped, and the light emission of the light source is controlled to perform projection exposure.

The above-mentioned optical reading means images a suitably illuminated barcode onto a line sensor using an objective lens, binarizes the output signal of the line sensor, and detects ID information by signal processing.

[Function] In the ID information recording/reading method with the above configuration, the image of the slit whose light emission is controlled is sequentially moved and stopped in accordance with the bar code on the projection exposure means of the recording device, and the image of the OF which is not used for the IC is A barcode is recorded in the area close to. The recorded barcode is imaged on a line sensor by an objective lens of an optical reading means provided in each IC manufacturing or testing device, and ID information is detected by processing the output signal of the line sensor.

[Embodiment] FIGS. 1(a) and 1(b) show an embodiment of the projection exposure means provided in the recording apparatus in the semiconductor wafer ID information recording/reading method according to the present invention. )
, the wafer 1 is placed on a suitable mounting table 1a, and a light source 4a, a slit 4b, and an imaging lens 4C are placed on the wafer 1.
A projection exposure device 4 is provided, which moves parallel to the OF in a region close to the OF of the wafer 1, and sequentially projects and exposes images of the slits 4b at positions corresponding to each bar of the barcode 3.

Projection exposure is carried out by coating the wafer 1 with a suitable photoresist agent in the same way as in the case of IC patterns, and after exposure, processing is performed using a developing and etching device to record the barcode 3. Although developing and etching equipment are not shown, those of the IC manufacturing equipment are used. Figure (b) is a circuit configuration diagram for step movement control of the projection exposure device 4 and light emission control of the light source 4a. In response to instructions from the microprocessor 6, the projection exposure device 4 is moved by the movement control circuit 5c and the movement mechanism 53. It moves stepwise to a position corresponding to each bar of the bar code and stops, and here the light source 4a emits light by the light emission control circuit 5b to project and expose the image of the sleeve 4b. FIG. 2 shows an embodiment of an optical reading means for ID information recorded by [-], in which a bar code 3 is scanned by an appropriate illumination 47.
of! (6 mornings, the image is focused on the line sensor 8b by the objective lens 8a. The line sensor 8b is a one-dimensional C
CI). The output signal of the line sensor 8b is binarized by the binarization circuit 9, each bar of the barcode 3 is detected, and the ID is
Information is decoded. The bit configuration of barcode 3 is:
Since it is only the manufacturing loft number and the individual wafer number,
A simple method is sufficient compared to a general method, and a decoding method or circuit for this can be easily constructed using a conventional technique, and therefore a description thereof will be omitted.

The optical reading device described in -1- below is installed in each IC manufacturing or testing device to read ID information.
Applies to wafer management at each stage.

[Effects of the invention] As is clear from the above explanation, the effects of this invention
In the ID information recording/reading method for conductor wafers,
Since the barcode is recorded in an area of the wafer that is not used for ICs, there is no problem or loss in the manufacture of ICs. Both the recording device and the barcode are simple, and the optical reading means is a simple one using a -dimensional line sensor, so it can be installed at a low cost in each IC manufacturing or inspection device, and can be installed in an IC manufacturing factory. The effect of streamlining the management of wafers is significant.

[Brief explanation of the drawing]

1(a) and (b) are block diagrams of an embodiment of a projection exposure means for recording/reading semiconductor wafer ID information according to the present invention, and FIG. 2 is a diagram of an optical reading means corresponding to FIG. FIG. 3, a configuration diagram of the embodiment, is an explanatory diagram of conventional ID information for a wafer. DESCRIPTION OF SYMBOLS 1... Wafer, la... Mounting table, 2... Character pattern, 3... Barcode, 4... Projection exposure device, 4a... Light source, 4b... Slit, 4c... - Imaging lens, 5b... Light emission control circuit, 6... Micro processor 8a... Objective lens, 9... Binarization circuit, 5a... Movement mechanism, 5c... Movement I control circuit , 7... Illuminator, 8b... Line sensor, IO... Signal processing section. Figure 1(a)

Claims (3)

[Claims] (1) On a wafer made of semiconductor IC material, ID information used to manage the wafer is recorded in an area close to the orientation flat (hereinafter abbreviated as OF) of the wafer using a projection exposure means installed in a recording device. A semiconductor wafer I, characterized in that a bar code representing the above is recorded, and the recorded bar code is read by an optical reading means provided in each of the above-mentioned IC manufacturing or inspection equipment.
D Information recording/reading method. (2) The projection exposure device of the projection exposure means transmits a light beam from a light source through a slit to the wafer, forms an image of the slit on the wafer using an imaging lens, and forms an image of the slit on the wafer. 2. The ID information recording/reading method for a semiconductor wafer according to claim 1, wherein the ID information recording/reading method for a semiconductor wafer is performed by sequentially stepping and stopping the bar code at an array position of the bar code, and controlling light emission of the light source to perform projection exposure. (3) The optical reading means images the suitably illuminated barcode onto a line sensor using an objective lens, binarizes the output of the line sensor, and detects ID information by signal processing. I of the semiconductor wafer according to item 1
D Information recording/reading method.