JP3928598B2 - Manufacturing method of semiconductor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor manufacturing method, and more particularly to a semiconductor manufacturing method manufactured using a dimension measurement pattern.
[0002]
[Prior art]
In the manufacturing process of semiconductor devices, dimension measurement in lithography is becoming an increasingly important position due to miniaturization.
[0003]
In the conventional dimension measurement, a dimension measurement pattern (usually one place) formed at an arbitrary position in a reticle (mask) is measured using a dimension measuring device such as a length measuring SEM, and within a predetermined dimension standard value or After confirming that the value was within the process control value, the process flowed.
[0004]
However, in a recent integrated circuit including a high-frequency amplifier circuit, that is, an analog circuit, simple OK / NG determination causes a reduction in circuit performance and a decrease in yield.
[0005]
Further, there are the following prior arts as conventional techniques.
A semiconductor chip located at an equal distance from the origin set in or out of the surface of the semiconductor wafer for the purpose of improving the processing accuracy in the surface of the semiconductor wafer by optimizing the exposure condition correction method in the lithography process On top of this, a resist pattern is formed under exposure conditions with the same correction, and the film formed on the semiconductor wafer is processed using the corrected resist pattern as a mask, so that the finished dimension of the processed film is uniform. (See Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-49076
[Problems to be solved by the invention]
However, in the conventional invention, in order to form a circuit pattern with high accuracy, a reticle (mask) in which predetermined dimension measurement patterns are formed at the four corners of the reticle shot is created, and the dimension measurement pattern at the four corners of the exposure shot is measured. In such a case, the length measurement value may vary due to the distortion of the lens of the exposure apparatus, and may deviate from the target dimension value.
The present invention has been made in view of the problem, and previously created a calibration curve in which the exposure amount and the dimension measurement value are plotted, and the average value of the dimension values of the four corners of the shot is compared with the calibration curve. If the difference is adjusted to the exposure amount, the target dimension value can be obtained with high accuracy.
In addition, when the calibration curve is created for each exposure apparatus, it is possible to obtain a predetermined dimension value with higher accuracy.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a method of manufacturing a semiconductor device according to claim 1 is the method of manufacturing a semiconductor device including a dimension measurement pattern , wherein the dimension measurement values are measured at a plurality of exposure amounts for the dimension measurement patterns at the four corners of the reticle shot. The average value is obtained by averaging the measurement process measured by the measurement process and the dimension measurement value measured by the measurement process , and is expressed by an equation represented by dimension value = slope × exposure amount + intercept derived from the average value. There is an averaging process for calculating the slope of the calibration curve that is a straight line, and a calculation process for calculating an initial average value that is an average value of the dimension measurement values obtained when the dimension measurement pattern is measured at a predetermined initial exposure amount. {Target dimension value-initial average value + (slope × initial exposure amount)} / a set exposure amount is obtained from a mathematical expression represented by a slope, and the substrate is exposed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will now be described with reference to the accompanying drawings.
FIG. 1 is a diagram in which the exposure amount and the dimension value are plotted.
POINT-1 to POINT4 represent dimension measurement patterns at the four corners of the shot, and Median represents an average value. Linear (Median) represents a straight line represented by an equation derived from an average value.
The above equation is displayed as follows:
Dimension value = -0.0006 x exposure amount + 0.6711
Here, -0.0006 represents the slope of the calibration curve, and 0.6711 represents the intercept. The actual work is to calculate the average exposure value obtained by measuring the dimension pattern at a predetermined exposure dose (in this case, 400 msec). For example, when the target dimension value is 0.450 μm, the set exposure dose is 0.437 μm. 378 msec.
[0014]
More specifically, the details are as follows.
Set exposure amount = {target dimension value−measured value + ( inclination × initial exposure amount)} ÷ inclination The numerical values given as examples above are described as follows.
378 = {0.45−0.437 + (− 0.0006 × 400)} / − 0.0006
It can be expressed as
[0015]
【The invention's effect】
As apparent from the above description, the semiconductor device manufacturing method of the present invention and the semiconductor device manufactured using the semiconductor device have a structure capable of measuring the dimensions of the four shot corners, and the dimensions of the four shot corners. The optimum exposure amount can be determined by comparing the measurement pattern measurement result with a calibration curve.
[Brief description of the drawings]
FIG. 1 is a plot of exposure amounts and dimension values in an embodiment of the present invention.

Claims (1)

In a method for manufacturing a semiconductor device including a dimension measurement pattern,
A measurement process for measuring a dimension measurement value at a plurality of exposure amounts for a dimension measurement pattern at four corners of a reticle shot;
An average value is obtained by averaging the dimension measurement values measured in the measurement step, and the calibration curve is a straight line represented by an equation represented by dimension value = slope × exposure amount + intercept derived from the average value. An averaging process to determine the slope ;
And a calculation step of calculating an initial average value is an average value of the resulting dimension measurement when measuring the dimension measurement pattern at a predetermined initial exposure,
{Target dimension value-initial average value + (inclination x initial exposure amount)} / A method of manufacturing a semiconductor device, wherein a set exposure amount is obtained from a mathematical expression represented by an inclination and the substrate is exposed.

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