JPH022103A - Aligner - Google Patents

Abstract

PURPOSE:To make it possible to make the dimension of patterns on semiconductor wafers constant regardless of error in the manufacture of photomasks by a method wherein photomask dimension measurement function is added to an aligner and exposure dose amount is varied according to the results of the measurement. CONSTITUTION:A photomask 3 having a pattern to be transferred is firstly fixed on an aligner. A measurement light flux 10 is radiated from a measurement light source 9 and it reaches a light receiving section 13 via the photomask 3 and a lens 12. Four patterns 11 for dimension measurement is positioned on the photomask 3, and its average value is determined. Next, this dimension measurement data is sent to a control system 8. In the case of the photomask 3 measured this time, it is calculated that how much of the exposure dose amount it to be adjusted to make the dimensions of a photoresist pattern on the semiconductor wafer 6 agree with a reference value, and an instruction is issued to a lighting optical system 1. Therefore, even when error in manufacture of two photomasks exists, the dimensions of the pattern on the semiconductor wafer 6 manufactured by using the two photomasks become the same.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exposure apparatus for transferring a photomask pattern onto a semiconductor wafer.

[Prior Art] FIG. 6 is a schematic diagram showing a conventional exposure apparatus.
(1) is an illumination optical system, (2) is an exposure light beam, (3) is a photomask, (6) is a semiconductor wafer, and (8) is a control system for the exposure apparatus. Further, FIG. 7 is a detailed view of the photomask (3), and in the figure, (14) is a transfer pattern drawn on the photomask (3). Also, Fig. 5<a>
In (15) is the photoresist pattern of the semiconductor wafer (6).

).

Next, the operation will be explained.゛A photomask (: ()) is used to form the pattern to be copied, and then a T4-body wafer (f) is coated with photoresist.
il is set. After that, an exposure light beam (2) is irradiated from the illumination light path 1 (1), and this light beam passes through the photomask (:l), 'i:i'-optical system (5).
l'-4 body wafer (ti) Transfer pattern (
14) Haircut the statue. At this time, one method of the photoresist pattern (15) depends on the dimensions of the pattern for rotation "!j':/(11).

[Problem to be Solved by the Invention] Conventional exposure apparatus: Although it was configured as above, it had the following problems.

Photomasks are manufactured according to a certain standard... Manufactured within the same standard 1, that is, according to the same standards,
Strictly speaking, the dimensions of the transfer patterns, which were tithes, are not equal even in the two photomasks that were manufactured in order to print the pattern of 7XJ-.

Now, assuming that these two photomasks are photomask (8) and photomask (1)), the relationship between the exposure dose arsenic and the photoresist is shown in the curve diagram in Figure 5 (al).
It becomes like this. When these two photomasks (8) and (B) are exposed at the same exposure dose (■ ((a)), the photoresist pattern (
15) dimensions do not match.

In order to match the photoresist pattern dimensions for the two photomasks (All), follow the steps in Figures 5(a) and (C).
), the exposure dose h1 for photomask (8) must be changed to (a).

However, a wafer production line usually does not have a method for knowing the pattern dimensions of photomasks, and even if it were known, it would be extremely difficult to carry out such management on a photomask.

Therefore, even if there are photomasks made to the same standard,
A problem arises when the pattern dimensions on a semiconductor wafer manufactured using the photomask (A) and the photomask (11) become circumferential.

This invention was made in order to solve the above-mentioned problems, and was developed by 3M in the production of transfer patterns on photomasks.
Regardless, it is assumed that the exposure apparatus 11 is capable of forming a certain 1-method photoresist pattern on a semiconductor wafer.

[Means for Solving the Problems] An exposure apparatus according to the present invention is provided with a mechanism for determining the dimensions of a photomasked transfer pattern, and the measuring mechanism is connected to an illumination optical system.

"Operation" The exposure apparatus of the present invention measures the method of transferring the pattern to the set photomask, and automatically changes the exposure dose according to the measured value.

[Embodiment] Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. In Fig. 1, (4) is a method measurement mechanism section, and this
The method measurement mechanism section is connected to the device control system (8). Fig. 2 is a detailed enlarged view of the dimension measurement mechanism section (4), in which (9) is the method measurement light source, (10) is the measurement light flux,
(II) is a dimension measurement pattern provided on the photomask (3), (12) is a lens, and (13) is a light receiving section. Further, FIG. 3 is a detailed diagram of j) of a photomask used in an embodiment of the exposure apparatus according to the present invention.

Next, the operation will be explained. A photomask (3) with a pattern to be transferred is first placed on an exposure device.

At this time, measure the dimension mark (1) on the photomask (3).
The positional relationship between 1) and the dimension measuring mechanism section is as shown in FIG. Next, a measuring light beam (In) is irradiated from the measuring light source (9), and this is applied to the photomask (3) and the lens (12).
) to the light receiving section (13). This light receiving part (13)
The illuminance distribution of the light reaching the area is as shown in FIG. 4, and by cutting this at a certain threshold value, the method of the dimension measurement pattern (l 1) can be found. In this example, the third
As shown in the figure, four dimension measurement patterns (11) are placed on a photomask (3), and the average value is calculated.

Next, this one-method measurement data is sent to the control system (8).

In the control system (8), the relationship between exposure dose 1 and photoresist dimensions as shown in FIG. 5(a) is determined in advance.
A certain reference photomask is memorized,
In the case of the photomask (3) measured this time, how much should the exposure dose (Ik) be adjusted to match the c quasi-value? and gives an instruction to the illumination optics + full).

Therefore, as shown in FIG. 5, two photomasks,
Even if there is a manufacturing error between photomasks (8) and (B), the semiconductor wafer (6) manufactured using both photomasks
) have the same pattern dimensions.

Incidentally, in the above embodiment, the dimension measurement pattern (11) of the photomask (:l) J: is provided at four locations on the outer periphery. You may arrange the number of. In addition, the case where the dimension measurement mechanism part (4) is a transmission type, +E reflection type,
It goes without saying that similar effects can be obtained by performing N1-method measurements using other principles such as the scattering method.

[Effects of the Invention] As described above, according to the present invention, a photomask dimension measurement function is added to an exposure apparatus, and the exposure dose is changed according to the measurement result, thereby reducing photomask manufacturing errors. Regardless of this, there is an effect that the pattern dimensions of the semiconductor uni-eight can be made constant.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an exposure apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view showing details of the measuring mechanism section of FIG. 1, and FIGS. 3(a) and 3(b) are Detailed views of the photomask, FIGS. 4(a) and 4(b) are diagrams of the measurement principle of the dimension measuring mechanism shown in FIG. A curve diagram and an explanatory diagram showing the relationship, FIG. 6 is a front view showing a conventional exposure apparatus, and FIG. 7 (
a) and (b) are detailed views of a conventional photomask. In the figure, (1) is the illumination optical system, (2)) is the photomask, and (1) is the illumination optical system.
4) is the dimension measurement mechanism section, (6) is the T-conductor wafer, (8)
is a control system, (11) is a dimension measurement pattern, (eye) is a transfer pattern, and (15) is a photoresist pattern. In addition, in the figures, the same reference numerals do not refer to the same or equivalent parts. Agent Masuo Oiwa Figure 3 Figure 4 Figure 1 Figure 2 Figure 5 (Q)

Claims (1)

[Claims] An exposure apparatus characterized by having a function of measuring dimensions of a photomask for semiconductor pattern transfer that is set on an exposure apparatus for manufacturing semiconductor wafers.