JPH01204419A - Charged beam exposure system - Google Patents

Abstract

PURPOSE:To improve positioning accuracy, by measuring the positioning accuracy of a cassette holder for fixing a wafer, adding the amount of accuracy to the scanning width of a charged beam, detecting a mark for positioning the wafer at the time of charged beam exposure, and determining the position of the wafer. CONSTITUTION:Before the detection of a mark 3 on a wafer 2, infrared rays or a laser beam 8 is projected on a recognizing mark 6 that is attached to a cassette holder 5. The cassette holder 5 that is used at that time is recognized with a detector 9. A signal of positioning accuracy inherent to the cassette holder is sent to a projection controller 11 with a signal processing means 10. The signal is inputted into a position controller 12 so that a charged beam 1a is made to scan by a distance obtained by subtracting the inherent error of the recognized cassette holder 5. The position controller 12 is controlled, and the charged beam 1a is made to scan on a mark 3 by the distance of the signal, and the position of the wafer is determined. Thus, the positioning accuracy of the wafer can be improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a charged beam exposure apparatus that exposes a desired pattern by irradiating a charged beam onto a resist that absorbs and reacts with charged beam energy on a substrate or a thin film. .

[Conventional technology]

Conventionally, when exposing a desired pattern by irradiating a charged beam onto a resist that absorbs and reacts with a charged beam on a substrate or a thin film, the wafer is fixed on a cassette holder and the marks made on the wafer are After positioning the wafer by detecting it with a charged beam, exposure to the charged beam is performed, and several different cassette holders are sequentially used to perform the exposure to the charged beam.

[Problem to be solved by the invention]

Since marks made directly on the wafer are used to position the wafer during charged beam exposure, the positioning accuracy (error) that occurs during the preparation of the cassette holders used to fix the wafer is approximately ±30. Therefore, when creating positioning marks on the wafer, it is necessary to create marks with a size that includes errors specific to the cassette holder.

For this reason, the drawing range on the wafer by the charged beam becomes narrow, and the accuracy of positioning the wafer is also low.

An object of the present invention is to provide a charged beam exposure apparatus that solves the above problems.

[Means to solve the problem]

In order to achieve the above object, the charged beam exposure apparatus of the present invention uses a charged beam to expose a desired pattern by irradiating a resist that absorbs and reacts with charged beam energy on a substrate or a thin film. In the exposure apparatus, a unique identification mark such as a grid or hole for recognizing the cassette holder provided on a cassette holder used for fixing the wafer, and means for detecting the identification mark of the cassette holder immediately before exposure to the charged beam; When positioning is performed by detecting marks created on the wafer during charged beam exposure, the positioning accuracy (error) unique to the detected cassette holder is measured in advance and raised as an offset. The device is equipped with a means for detecting a mark and a means for exposing the wafer to a charged beam after positioning the wafer.

[Effect]

The positioning accuracy of several different shaped wafer fixing cassette holders used is measured in advance, and the accuracy is increased to the scanning width of the charged beam to improve wafer positioning during charged beam exposure. In order to position the wafer by detecting marks, the positioning marks made on the wafer are changed from about 2004' to about 1404' and about 604'.
'The exposure range by the charged beam on the rewafer, which can be made smaller, becomes wider, and the positioning accuracy improves by ±30p.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to embodiments and drawings thereof.

FIG. 1 is a block diagram showing an example of a charged beam exposure apparatus embodying the present invention. In FIG. The cassette holder 5 is provided with an identification mark unique to the holder, such as a grid or It has 66. On the other hand, the detection means for the identification mark 6 includes an infrared ray or laser device 7 and a detector 9 for detecting the infrared ray or laser 8 transmitted through the grid or 66 of the identification mark 6. It is controlled based on the signal of 9, and is provided with a signal processing means 10, an irradiation control device 11, and a position controller 12 as its control means. The signal processing means 10 stores the positioning accuracy (error) unique to each cassette holder measured in advance for each cassette holder to be used, and the irradiation control device 11 receives the positioning accuracy signal for the recognized cassette holder. The position controller 12 uses the output signal to detect the mark 3 and drive the position deflector 4.

The specific control procedure is performed in the following order. That is,
On the way, the charged beam 1a passes through an irradiation lens, a shaping lens, a reduction lens, and an objective lens (all paths shown in the figure), is scanned by a position deflector 4, and a mark 3 on the wafer 2 is detected. Prior to this mark detection, an identification mark 6 made of a grid or a hole attached to the cassette holder 5 is irradiated with infrared rays or a laser beam 8 emitted from a laser device 7, and a detector 9 detects the cassette being used at the time. The holder 5 is recognized, and the signal processing means 10 sends a signal indicating the positioning accuracy (error) specific to the cassette holder to the irradiation control bag [11], and the charged beam is emitted by a distance equal to the error specific to the recognized cassette holder 5. A signal is input to the position controller 12 to scan the wafer 1a, and the position controller 12 is controlled to scan the charged beam 1a over the mark 3 by the distance of the signal, thereby positioning the wafer 2.

Next, a desired pattern is exposed to a charged beam.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to position the wafer without including the positioning accuracy (error) inherent in the cassette holder for fixing the wafer, and as a result, the marks made on the wafer can be made smaller. This has the effect of expanding the writing range of the charged beam on the wafer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1...Charged beam gun 1a...Charged beam 2...Wafer 3...Mark 4...
・Position deflector 5...Cassette holder 6...Identification mark by grid or hole 7...Infrared rays or laser device 8...Infrared rays or laser 9...Detector 10.
...Signal processing means 11...Irradiation control device 1
2...Position controller Figure 1

Claims (1)

[Claims] 1. A cassette installed in a cassette holder used to fix a wafer in a charged beam exposure device that exposes a desired pattern by irradiating a charged beam onto a resist that absorbs and reacts with charged beam energy on a substrate or thin film. A unique identification mark such as a grid or hole for holder recognition, a means for detecting the identification mark of the cassette holder immediately before exposure to a charged beam, and a positioning method by detecting marks made on the wafer during exposure to a charged beam. In this case, a means for detecting the mark by increasing the positioning accuracy (error) unique to the detected cassette holder, which has been measured in advance as an offset, and a means for detecting the mark by increasing the positioning accuracy (error) unique to the detected cassette holder in advance, and after positioning the wafer, the charged beam 1. A charged beam exposure apparatus comprising: means for exposing.