JPS594850B2 - hand tai souchi no seizou houhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device, particularly a photoetching method that requires dimensional accuracy.

Although the photo-etching method is an indispensable method in the manufacture of semiconductor devices, the dimensions of the figure that is finally etched off often vary depending on exposure conditions, etching conditions, etc.

It is well known that variations after photoetching, such as gate length of junction type or Schottky barrier field effect transistors and emitter width of bipolar transistors for ultra-high frequency applications, have a large impact on characteristics such as power gain and breakdown voltage. . Conventionally, when controlling or inspecting the dimensions of the above-mentioned figures, the actual dimensions have been measured using a micrometer or the like.

In this case, when the maximum deviation value of dimensional variation is less than 1 μm, the mechanical accuracy of the measuring jig becomes a problem, and the measurement is extremely difficult. 5. The invention was made in view of the above-mentioned conventional circumstances, and therefore, the purpose of the present invention is to eliminate the trouble of measuring the actual dimensions of a figure after photo-etching, and to improve the mechanical accuracy of jigs, etc. Easily and accurately determine whether the shape is within the allowable dimensional variation range without the need for
An object of the present invention is to provide a novel method for manufacturing a semiconductor device that can make a zero determination.

Another object of the present invention is to provide a new method for easily manufacturing semiconductor devices with various good electrical characteristics.

15. The above object of the present invention is to simultaneously photo-etch at least one pair of dimensional inspection patterns during photo-etching of an insulating film or metal adhesion layer formed on a semiconductor substrate; Set the extension line of at least 20 line segments on one side of one of the dimension inspection figures to be parallel to the line segment on one side of the other figure, and This is achieved by a semiconductor device manufacturing method characterized by inspecting the dimensions of a figure to be etched based on distance.

25 The method for manufacturing a semiconductor device according to the present invention uses a plurality of dimensional inspection patterns that are photo-etched simultaneously during photo-etching of an insulating silicon compound or metal adhesion layer formed on a semiconductor substrate, and Among a set of 30 figures forming at least a pair of dimension inspection figures, the extension line of at least one side of one figure is parallel to the line segment of one side of the other figure and is at a distance of the maximum allowable dimensional variation deviation value. The present invention is characterized in that the dimensions of the object to be photo-etched are inspected by moving line segments between the dimension inspection figures.

35 Next, preferred embodiments of the present invention will be specifically described with reference to the accompanying drawings.

In one embodiment of the method according to the invention, a pattern to be etched requiring dimensional accuracy, such as that shown in FIG. 1, and a dimensional inspection pattern, such as that shown in FIG. 2, are simultaneously etched on the same substrate.

Figure 1 shows a figure that requires dimensional accuracy. Figure 1 has a width of the design center value W, and the maximum deviation values of dimensional variation are l/2 and u/2, that is, the dimensional variation after photoetching. It is assumed that the allowable range is from W-l/2 to W+u/2. FIG. 2 shows an example of the basic form of the dimensional inspection figure used in the method according to the present invention, and it is placed at an appropriate position on the same substrate as the figure 1 that requires dimensional accuracy shown in FIG. They are photo-etched at the same time, and show the state when figure 1 is photo-etched to the design center value range. To explain FIG. 2 in more detail, the straight line 4 that includes the line segment 2x, that is, the extension line of the line segment 2x of the figure 2.
Straight line 5x including x and line segment 3x of figure 3 is each figure 3
is a parallel line that passes through (penetrates) figure 2 and is separated by a distance l. Similarly, straight line 4y including line segment 2y of figure 2 and straight line 5y including line segment 3y of figure 3 are parallel lines separated by distance u and do not pass through figures 3 and 2, respectively. Dimensional inspection figures 2 and 3 shown in Fig. 2 are a pair of figures, and if these figures 2 and 3 satisfy the above conditions, figure 1 shown in Fig. 1 is a designed one. It is determined that the image has been photoetched to the center value width W. At that time, parallel lines (
In the example shown in FIG. 2, the straight lines 4x and 5x) are used as a criterion for determining whether figure 1 has been finely etched to within the dimensional variation tolerance range W-l/2, and on the other hand,
Parallel lines (straight lines 4y and 5y in the example in Figure 2) consisting of straight lines that do not pass through other figures that are paired with each other are figure 1.
This is used as a criterion for determining whether or not the photo has been photoetched thicker than the allowable dimensional variation range W+u/2. In the example shown in FIG. 2, the straight lines 4x, 5x
is a straight line that passes through other figures that are paired with each other, and straight lines 4y and 5y are defined as straight lines that do not pass through other figures that are paired with each other. It goes without saying that the positions of figures 2 and 3 may be displaced so that the other figures forming the pair are straight lines that do not pass through them, and the straight lines 4y and 5y are straight lines that pass through the other figures that are paired with each other. .
Further, the dimension inspection figure does not have to be a quadrilateral and may include a curved line as a part thereof. Furthermore, the length of one side of the dimension inspection figure is arbitrary. If figure 1 in Figure 1 is the dimensional variation tolerance W
If it is thinly photoetched to less than -l/2,
Since the line segments 2x and 3x of the dimension inspection figures 2 and 3, which were photoetched at the same time, move inward of the figures 2 and 3 by more than a distance l, the lines 4x and 5 are shown in FIG.
x no longer passes through figure 3 and figure 2, respectively.

When photoetched to W-l/2, which is the lower limit of the allowable dimensional variation range, the straight lines 4x and 5x coincide and overlap. Also, if figure 1 in Figure 1 is within the dimensional variation tolerance range W+
If the photo is thicker than u, the line segments 2y and 3y of the dimension inspection figures 2 and 3 will move outward of the figures 2 and 3 by a distance u or more, so the line 4y will become the straight line 4y as shown in Fig. 4. and 5y pass through figure 3 and figure 2, respectively. Needless to say, at the same time, the line segments 2x and 3x of figures 2 and 3 are also moved outwardly of figures 2 and 3 by a distance u or more. Therefore, if the extension line 4x of line segment 2x of figure 2 passes through figure 3 in Figure 2, and the extension line 4y of line segment 2y of figure 2 does not pass through figure 3, the dimensional accuracy in Figure 1 will be reduced. The required figure 1 is photoetched within the allowable range of dimensional variation.

As described above, according to the present invention, it is possible to directly check with a microscope or the like whether or not the dimensional variation is within the permissible range based on the dimensional inspection pattern without measuring the actual dimension.

Moreover, regardless of the width W of the figure 1 which requires dimensional accuracy, the relative position of each side of the dimension inspection figure is determined only by l/2 and u/2 of the maximum deviation value of the dimensional variation. It is clear that the portion of figure 1 to be photoetched may be the figure 1 itself, that is, the shaded area, or the surrounding area of figure 1. It goes without saying that the portions to be photographed may be the figures 2 and 3 themselves, that is, the shaded areas, or the portions surrounding the figures 2 and 3.

FIG. 5 shows another example of dimensional inspection figures used in the method of manufacturing a semiconductor device according to the present invention, in which two figures 2 and 3 shown in FIG. 2 are used as parts not involved in dimensional inspection. 2
Although they are connected at point a to form one figure, they are functionally the same as the two figures in Figure 2, and in the case shown in Figure 5, Figures 2 and 3 are paired. shall be included within the range of a set of figures.

In this way, the dimension inspection figures are not intended to be limited to the range shown in FIG. 2, FIG. 5, or FIG. It goes without saying that other variations and changes can be made. FIG. 6 shows another example of a dimension inspection figure used in the method according to the present invention, which is designed to make it easier to visually inspect dimensions than the figure shown in FIG.

Reference numerals 10, 20, 30, and 40 are dimensional inspection figures that are photoetched at the same time as figure 1 in FIG. 1, which requires dimensional accuracy. is doing. Each figure in FIG. 6 shows the state when figure 1 is photoetched to the design center value range. l/2 and u/2 are the maximum deviation values of dimensional variation, as described above. FIG. 6 will be explained in more detail. The straight line 51x includes the line segment 11x of the figure 10 and the line segment 31x of the figure 30, is parallel to the line segment 20x of the figure 20 at a distance of l, and also passes through the figure 20. or,
The straight line 52y includes the line segment 22y of the figure 20 and the line segment 42y of the figure 40, is parallel to the line segment 30y of the figure 30 at a distance of u, and does not pass through the figure 30.
Similarly, the straight line 52x is the line segment 32x of the figure 30 and the figure 10.
It includes a line segment 12x of the figure 40, is parallel to the line segment 40x of the figure 40 at a distance of l, and also passes through the figure 40.
The straight line 51y includes the line segment 21y of the figure 20 and the line segment 41y of the figure 40, is separated by a distance u from the line segment 10y of the figure 10, and does not pass through the figure 10. In the case of FIG. 6, the straight line 51x, which is an extension of the line segment 11x of the figure 10 and the line segment 31x of the figure 30, has line segments 11x and 31x on both sides of the figure 20, so the straight line 4x of FIG. It is now easier to detect visually.

Similar effects can be obtained with the straight lines 52x, 51y, and 52y. Figure 7 shows the 6th figure that was photoetched at the same time when Figure 1, which requires dimensional accuracy in Figure 1, was thinly photo-etched to within the dimensional variation tolerance W-l/2.
It represents the dimension inspection figure of the form shown in the figure.

Further, FIG. 8 shows a dimensional inspection pattern that is photoetched at the same time when the pattern 1 shown in FIG. 1, which requires dimensional accuracy, is photoetched to be thicker than the dimensional variation allowable range W+u/2.

Therefore, in FIG. 6, the extension line 51x of the line segment 11x of the figure 10 and the line segment 31x of the figure 30, and the extension line 52x of the line segment 12x of the figure 10 and the line segment 32x of the figure 30 are the figure 20.
, through the figure 40, and the line segment 21y of the figure 20, the extension line 51y of the line segment 41y of the figure 40, and the line segment 2 of the figure 20.
2y and the extension line 52y of the line segment 42y of the figure 40 do not pass through the figures 10 and 30, respectively, the figure 1 which requires dimensional accuracy shown in FIG. 1 is photoetched within the dimensional variation tolerance range.

The present invention is constructed as described above, and the present invention is capable of photo-etching a dimension inspection figure at the same time as a figure to be etched which requires dimensional accuracy, and by observing the etched state of the dimension inspection figure. Since this is a method for determining whether or not a figure has been etched within an allowable range of dimensional variation, the present invention eliminates the troublesome measurement of the actual dimensions of the figure to be etched after photo etching, and also eliminates the need for tools such as jigs, etc. This method has the advantage that it is possible to easily and accurately determine whether or not the figure to be etched is within the allowable dimensional variation range without requiring mechanical precision.

Although the present invention has been described above with reference to the preferred embodiments thereof with reference to the accompanying drawings, it goes without saying that these are merely illustrative and do not have a restrictive meaning.
Accordingly, the present invention may be practiced with various modifications without departing from the spirit and scope of the invention, but all such modifications are included within the scope of the claims of the present invention.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a figure that requires dimensional accuracy in photoetching, FIG. 2 is a diagram showing an example of the basic form of a dimensional inspection figure used in the semiconductor manufacturing method according to the present invention,
Figures 3 and 4 are diagrams showing dimensional inspection figures that are outside the allowable dimensional variation range, and Figure 5 is a modification of Figure 2, showing other examples of dimensional inspection figures used in the method according to the invention. FIG. 6 is a diagram showing still another example of a dimension inspection figure used in the method according to the present invention, and FIGS. 7 and 8 are diagrams showing a dimension inspection figure outside the allowable range of dimensional variation. .

Claims (1)

[Claims] 1. In a semiconductor device manufacturing method including a photo-etching step, at least one pair of dimension inspection figures is simultaneously photo-etched during photo-etching, and a line segment on at least one side of one of the dimension inspection figures is A method for manufacturing a semiconductor device, characterized in that the dimension of the figure to be etched is inspected based on the distance between the two parallel sides of each dimension inspection figure, with the figure being set to be parallel to a line segment on one side of the other figure. .