JPH0578167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam exposure apparatus, and relates to a drawing positioning method using an electron beam for so-called mask drawing in which a desired mask pattern is drawn on a sample by an electron beam, and a sample of the electron beam exposure apparatus. It concerns the holder.

In an electron beam exposure apparatus, when a desired mask pattern is drawn on a sample by irradiating an electron beam, the following procedure has conventionally been used. That is,
First, an electron beam scans the reference mark at the drawing position installed outside the stage that makes up the drive system, the mark position is calculated from the signal from the reflected electrons, and the known mark position is used as a reference. A pattern is drawn at a desired position on a sample. However, during drawing using an electron beam, the position of the drawing pattern shifts due to the influence of drift of the electron beam in the electron optical system of the exposure apparatus. In order to correct this deviation, conventional methods correct the drift component by scanning a reference mark set outside the stage with the electron beam at time intervals that minimize the drift of the electron beam during writing. Was. FIG. 1 shows the structure of a stage 3 and the position of a reference mark 4 in a drive system of a conventional exposure apparatus. A sample 1 is fixed to a sample holder 2 and loaded onto a stage 3. In addition, the reference mark 4 is located outside the stage 3 and the sample 1
is placed on the same plane. however,
This structure in which the reference mark 4 is installed outside the stage 3 has the following problems. First, the stage generates heat due to electron beam irradiation and frictional heat due to the movement of the stage, so the stage expands volumetrically, resulting in a deviation in the drawing position from the reference mark 4. . Furthermore, in order to reduce the weight of the stage 3, the material used for the stage 3, such as Al, which has a large coefficient of thermal expansion, is greatly affected by heat generation.
When drawing a Si wafer as a second sample, the volume of the Si wafer increases due to heat generation due to electron beam irradiation and heat conduction from the stage, since Si has a large coefficient of thermal expansion. As a result, in order to deal with deviations in the drawing position from the reference mark, the mark position is calculated by scanning only one reference mark installed outside the stage with an electron beam at appropriate time intervals, and this is used to calculate the mark position. The deviation from the drawing position is corrected, and the effect of deviation of the drawing position from the reference mark due to heat generation in the stage or sample is also corrected by polarizing the beam by regarding it as being due to the drift of the electron beam. I'm just doing it. As a result, the correction is inevitably insufficient, and it has been impossible to obtain a satisfactory mask pattern with a small deviation from the desired drawing position using conventional drawing methods.

The object of the present invention is to provide a drawing positioning method using electron beam exposure and a sample holder for an electron beam exposure apparatus, which can eliminate such conventional drawbacks and form a mask pattern on a sample with a small deviation from a desired drawing position. It's about doing.

That is, the present invention provides a drawing positioning method using electron beam exposure of an electron beam exposure apparatus that draws a mask pattern on a sample using an electron beam. The present invention is characterized in that a drawing position on a sample is determined based on a mark marked on a member, and the present invention also provides a sample holder for an electron beam exposure apparatus that draws a mask pattern on a sample with an electron beam. An annular member made of the same material as the sample is disposed on a concentric circle around the specimen, and a reference mark for the drawing position is marked on the annular member.

Embodiments of the present invention will be described below with reference to the drawings.

In Figure 2, a sample wafer 1 is fixed in the center, and an annular wafer 5 made of the same material as sample 1 is placed outside.
This is a sample holder 2 which is fixed concentrically with the sample 1. A mark 6 indicating a reference position for pattern drawing is attached to this annular wafer 5. In this embodiment, a total of 4 wafers, one each, are placed on the orthogonal axis passing through the center of the annular wafer 5.
An example is shown in which each is provided. These four marks 6 are scanned with an electron beam, signals from reflected electrons are detected, the position of each mark is calculated, and expansion/contraction and rotational displacement of the wafer are corrected based on the signals.
In the present invention, since the mark indicating the reference position is set on the same material as the sample wafer, changes in the shape of the sample wafer due to temperature rise in the sample chamber directly correspond to changes in the position of the mark. By using the mark position as a reference, the drawing position can be determined regardless of the temperature inside the sample chamber. Furthermore, since the marks are set not on the sample but on the annular wafer, if this is used in a semi-fixed manner for sample exchange, the step of resetting the marks can be omitted.

Although the above embodiment describes the case where a wafer is used as a sample, it is not limited to this.
For example, the same effect as described above can be obtained when a glass plate or a quartz plate is used.

As described above, according to the present invention, a highly accurate mask pattern can be obtained by reducing the deviation of the drawing position during pattern drawing, and the work can be performed efficiently by exchanging only the sample. It is something that you have.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional stage, and FIG. 2 is a plan view showing an embodiment of a sample holder according to the present invention. 1... Wafer, 2... Sample holder, 3... Stage, 4... Mark, 5... Wafer, 6... Mark.

Claims (1)

[Scope of Claims] 1. In a drawing positioning method using electron beam exposure of an electron beam exposure apparatus that draws a mask pattern on a sample with an electron beam, a mask pattern is placed on a concentric circle around the sample and is made of the same material as the sample. A drawing positioning method using electron beam exposure, characterized in that a drawing position on a sample is determined based on a mark marked on an annular member. 2. In a sample holder of an electron beam exposure device that draws a mask pattern on a sample with an electron beam, an annular member made of the same material as the sample is placed on a concentric circle around the sample, and the annular member is used as a reference for the drawing position. A sample holder for an electron beam exposure apparatus characterized by having a mark.