JPS5969917A - Discriminating method for semiconductor wafer - Google Patents

Abstract

PURPOSE:To simplify a process required for discriminating a wafer information, to shorten time required for discrimination and to miniaturize related devices by writing a ring-shaped bar code mark on the semiconductor wafer in an approximately concentrical shape to the wafer. CONSTITUTION:The ring-shaped bar code mark 4 is written on the back (the surface) of the semiconductor wafer 1 through photoetching or laser marking or the like in the approximately concentrical shape to the wafer 1 as the wafer informations. The contents of the wafer informations are represented according to the number of rings, width of the rings or combination of each ring width, mutual spaces of the rings or combination of each space, etc. of the bar code mark 4. The wafer 1 is passed in the arbitrary direction so that the mark 4 crosses in the radial direction and the mark 4 is read at the position of reading of a reading device. The mark 4 of the same pattern is read regardless of the directions of the wafer 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for identifying wafer information (such as put information) of a semiconductor wafer in a semiconductor device manufacturing process.

[Technical background of the invention]

When automating semiconductor manufacturing processes, it is desirable to automatically identify wafer information such as semiconductor wafer lot numbers, and to set process conditions and register process QC (quality control) data based on the identification results.

By the way, conventionally, as shown in FIG. 1, marks 3 such as numbers, symbols, alphabetic characters, etc. are engraved on the orientation flat portion 2 of the semiconductor wafer 1 by a method such as photo-etching or laser marking as the wafer information. are doing. In order to read the mark 3 such as a number, the reading part of the wafer mark cutting and picking device is placed on the mark 3 part of the semiconductor wafer 1 in a predetermined direction (direction that matches the reading direction of the mark 3). They are facing each other.

[Problems with background technology]

However, in the conventional semiconductor wafer identification method as described above, when including and reading mark 3, positioning is required to precisely align the position of n semiconductor wafer 1 and to match its orientation to the orientation of mark 3. Since a device and an alignment process are required, there are disadvantages in that the wafer information needs to be read, the device becomes large, and the time required for writing and reading is long. In addition, when multiple reading systems are used to read nine information at each stage of the semiconductor device process, it is necessary to maintain compatibility in alignment for each reading system. The configuration of each device became complicated, and maintenance of each device was troublesome.

[Purpose of the invention]

The present invention has been made to eliminate the above-mentioned drawbacks; it is not necessary to completely adjust the orientation of the wafer when corrupting or reading wafer information, and the process required for identifying wafers and information is simplified; The present invention provides a semiconductor wafer identification method that reduces the time required for the process and reduces the size of related equipment.

[Summary of the invention]

That is, the semiconductor urchin identification method of the present invention involves writing a ring-shaped barcode mark on a semiconductor wafer approximately concentrically with the wafer, reading all the barcode marks on the wafer during the semiconductor device manufacturing process for this wafer, and reading this barcode mark on the wafer. This method is characterized in that wafer information is identified based on the cystectomy results.

Therefore, since the wafer and the wafer 11 use concentric barcode marks, there is no need to adjust the orientation of the wafer when writing and reading the wafer, and the process for identifying p1 is simple. Example] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In the present invention, first, as shown in FIG. 2, for example, a ring-shaped barcode mark 4 is placed approximately concentrically with the wafer 1 as wafer information on the back surface (or the front surface) of the semiconductor wafer 1. Writing is performed by a known method such as photo etching or laser marking. In this case, alignment is performed to the extent that the center of the semiconductor wafer 1 approximately coincides with the writing center of the writing device, but the orientation of the wafer 1 and the orientation of the flat portion 2 may be arbitrary. Also, depending on the number of rings (one or more) in the ring-shaped barcode mark 4, the width of the rings or a combination of widths of each ring, the mutual spacing of the rings or the combination of the spacings, etc. It is defined to represent the content of the information.

Next, when it is necessary to read the wafer information 1 (for example, when setting process conditions in the semiconductor device manufacturing process for the wafer), the reading position m by the reading unit of the barcode mark reading device is: Ueno 1 so that the code mark 4 crosses in the radial direction.
The mark 4 is read by passing it in any direction. In this case, the same pattern of barcode mark 4"f:H should be taken regardless of the orientation of the wafer l. For example, if the barcode mark 4 is carved as a groove on the wafer l by laser marking, All mark detection is performed by a laser light sensor by utilizing the difference in the round trip distance of the laser light due to the difference in level between the groove and the wafer surface.

In addition, the mark 4 is read twice so that, for example, one diameter line part of the reading #9 all wafers 1 passes through it,
Or, one radius line of the wafer 1 passes from the center to the outer edge or vice versa.
Even if the mark reading signal is read once, it is possible to guide the mark reading signal to the entire barcode decoding processing device to identify the mark contents. In this case, it is necessary to align almost the entire center of the wafer I with the reading center position of the reading device, but since a normal semiconductor process includes a step of aligning the center of the wafer, this step can be used.

Furthermore, if the reading device is configured to scan the blue light, the mark 4 can be read simply by placing the wafer l' on the reading device.

Note that FIG. 3 shows an example of a system for reading all wafer information and setting process conditions. Reference numeral 10 denotes a semiconductor manufacturing apparatus, in which a plurality of semiconductor wafers 1 are housed in a carrier 11 placed on an input chamber. A Ueno S information reading device 12 is installed opposite to the conveyance path of the wafer 1, and the barcode mark reading data by this device 12 is guided to the reading device controller 13, where the uni/strip number is decoded. . This wafer number data is read into the host computer 14, where the process conditions are determined, and the manufacturing equipment controller 15 controls the manufacturing equipment 1θ according to the determined conditions.
Perform all condition settings. Note that 16 is an external memory, and 17 is a carrier on the output stage of the manufacturing apparatus 10. Further, the reading device 12 may be located on a carrier station such as a loader or on a conveyor belt as long as it is on the conveyance path of the wafer 1.

According to the semiconductor wafer identification method described above, a concentric ring-shaped barcode mark is inserted into the wafer information as wafer information, and when reading the mark, the reading device and the wafer are connected to each other. By making the wafers face each other regardless of their orientation, and by using the process of determining the center position of the wafer in the normal process when shaving and reading the above marks, there is no need for special wafer alignment gold coins, as mentioned above. There is no need for alignment steps and devices for mark identification, which were conventionally necessary. Therefore, the process and equipment required to identify wafer information are simplified, and the time required for n% identification is shortened, making it suitable for miniaturizing writing and reading equipment and automating the process processing condition setting system. There is. Furthermore, even when a plurality of reading devices are used, there is no need for each positioning device, and troublesome maintenance of the positioning devices becomes unnecessary.

〔Effect of the invention〕

As described above, according to the wafer identification method of the present invention, there is no need to adjust the orientation of the wafer when inserting and reading wafer information, simplifying the steps required to identify wafer information, and reducing the time required for identification. It is possible to shorten the time and downsize the related equipment, and it is suitable for automating a process treatment condition setting system.

[Brief explanation of drawings]

FIG. 11 is a plan view shown to explain conventional marks on a semiconductor wafer, and FIGS. 2 and 3 are an embodiment of the wafer identification method according to the present invention. This is shown for the purpose of explanation.
Figure 2 is a plan view showing a state in which barcode marks have been written on a semiconductor wafer, and Figure 3 is a configuration diagram showing a system for reading the barcode marks in Figure 2 and setting process conditions for semiconductor device manufacturing equipment. , is a cut. 1... Semiconductor sea urchin / 1.4... Ring-shaped (- code mark. Applicant's representative Patent attorney Takehiko Suzue 57

Claims (1)

[Claims] A ring-shaped barcode mark is written on a semiconductor wafer almost concentrically with the wafer by a mark writing device, and this barcode mark is written on the wafer by a barcode mark reading device during the semiconductor device manufacturing process for the wafer. A semiconductor wafer identification method comprising reading a barcode mark and identifying wafer information of the wafer based on the read barcode mark.