JPS6142915A - X-ray mask transfer apparatus - Google Patents

Abstract

PURPOSE:To perform positioning in high accuracy by a method wherein a substrate stage is controlled so that the output of an X-ray sensor located at the back side of a substrate indicates max. when X-ray is exposed on only each mark part of an X-ray transfer mask and a semiconductor substrate by using an X-ray shutter. CONSTITUTION:X-ray from an X-ray generator 4 is given to a mark 10a of a mark 2 and a mark 8b of a semiconductor substrate 1 through an aperture 3a of a shutter 3, the X-ray beam of a small diameter is given to an X-ray sensor 5. A controller 7, using the sensor output signal, controls a substrate stage so that the max. sensor signal output is obtained. Thereby, positioning in high accuracy within a short time is enabled by using the X-ray from the X-ray generator to be used for transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to an X-ray mask transfer device for transferring a mask pattern of an X-ray transfer mask onto an X-ray resist film on a T-single conductor substrate.

(0) Conventional technology ゛゛Recent progress in semiconductor integrated circuits has been remarkable.

Further densification 1, direction towards higher integration, TEPMIC 6
Research on VLSIs that use the same pattern is being actively pursued. With the ring graph technology, which holds the key to pattern miniaturization, it is becoming possible to use ultraviolet light exposure down to around 1 μm due to the development of reduction projection exposure methods and advances in optical systems. Such restrictions will become stricter.

Due to its high resolution, the XJi1 transfer technology is considered to be the only transfer technology applicable to pattern areas of 0.5 μm or less. In the X-ray transfer method, a proximity method is employed in which a single conductor substrate and an X-ray transfer mask are held at an interval of about 10 μm and exposed. By this method, it is fully possible to form a pattern of α5 μm or less, and the submicron resolution has reached a level close to practical use. However, although the pattern alignment accuracy required for manufacturing elements having a 0.5 μm pattern is about ±0.05 μm, the conventional X-ray transfer method cannot achieve the required alignment accuracy. The reason for this is thought to be that although X-rays are used for pattern exposure, a method using light is used to align the mask and the semiconductor substrate. The current alignment accuracy using light is ±
The limit is about 0.1 μm. (Refer to 1! Child Communications Society Technical Research Report 13sDB2-178) (/9 Problems to be Solved by the Invention In the conventional device, as described above, the alignment of the semiconductor substrate and the X-ray transfer mask is done by marking attached to both. Since the positioning accuracy is optically read and controlled, the positional accuracy is limited to about ±0.1 μm, and the present invention was created in view of this problem, which was accompanied by difficulties in pattern exposure on the submicron order. It is an object of the present invention to provide an X-ray mask transfer device that can perform the above-mentioned mark positioning using t-X rays with even higher accuracy.

B.) Means for Solving the Problems The present invention provides an X-ray transfer mask prior to transferring an exposure pattern to an X-ray resist on a semiconductor substrate by applying X-rays from an X-ray generating section to an X-ray transfer mask. The alignment of the mask and the semiconductor substrate can be controlled using the X-rays. That is, the present invention uses a shutter to irradiate X-rays from an X-ray generator only to each mark portion of an X-ray transfer mask and a semiconductor substrate, and detects the output of an X-ray sensor on the back side of the semiconductor substrate. It is configured to control the substrate stage on which the semiconductor substrate is placed so that the output is maximized.

(e) Action X-rays travel through materials with better linearity than light or electron beams, and are less susceptible to interference and scattering.
The amount of X-rays applied from the X-ray generator to the X-ray sensor through the alignment marks of the radiation transfer mask and the alignment marks of the semiconductor substrate is determined according to the positional relationship of each alignment mark, and the amount of irradiation is By controlling so that the sensor output based on this value is maximized, it is possible to match the position relationship f of both marks with high precision.

(f) Practical Example FIG. 1 is a schematic configuration diagram of one embodiment of the device of the present invention, FIG. 2 is a partial sectional view of a semiconductor substrate, and FIG. tx3 is a waveform diagram of the senna output.

In Fig. 1 h, (1) is a semiconductor substrate, (2) is an X-ray transfer mask, (3) is a shutter, (4) is an X-ray generation part,
(5) is a Xi sensor, (6) is a substrate stage, and (71 is a controller) 0-ra.

The semiconductor substrate fi+ is provided with a plurality of through holes (8) (21 in the figure) used as alignment marks.

Each through hole (8) has a diameter Ce of the opening (8a) on the back side of the board.
), the diameter of the opening (8b) on the board surface side is extremely
It is shaped like a small pinhole. An X-ray resist film (9) is spin-coded over the entire surface of the semiconductor substrate (1).

The X-ray transfer mask (2) is arranged at predetermined intervals on the upper blade of the semiconductor substrate (1), and has a mask pattern (101) including alignment marks (IQa) corresponding to the through holes (8). h.The shutter (3) selectively allows a part of the X-ray αD from the X-ray generator (4) to pass through, and the shutter (3) selectively allows a portion of the X-ray αD from the X-ray generator (4) to pass through only when aligning the mask. It is configured so that it can be inserted between the transfer masks [2].

X selected at the opening (6a) of this shutter (3)
The line (1)a) is configured to be applied to each mark on the mask (2) and the semiconductor substrate (1).

The X-ray sensor (5) is arranged on the back side of the single conductor substrate (1) so as to face the through hole (8). The sensor output of this X-ray sensor (5) is applied to the controller (7) through the lead (5a). Substrate stage (6
) are supported by the semiconductor substrate (1) and the X-ray sensor (5), and are constructed so that they can be moved arbitrarily within one plane. The controller (7) analyzes the senna output from the X-ray sensor (5) and sends the upper conductor board (
The movement of the substrate stage (61) is controlled so that the marks on the X-ray transfer mask (2) and the X-ray transfer mask (2) coincide with each other.

t, that is, the X-rays from the X-ray generator (4) pass through the shutter (3
) through the opening (3a) of the mask (2).
0a) and the mark (8b) on the semiconductor substrate (1), and a minute diameter X-ray is applied to the X-ray sensor (5) - the output of this sensor is as shown in FIG. The horizontal axis indicates the position f of the substrate stay V (6), and the vertical axis (131 indicates the signal strength).The controller (7) receives this sensor output and determines the signal strength for the substrate stage (6). The control output is made to increase.

Next, the present embodiment will be explained in further detail including numerical examples and the like. The semiconductor substrate (1) is attached to a 3-inch ψ silicon plate, and through holes (8) are formed on this 'is=no1 at 20u intervals.
I am observing at two locations. Each through hole (81 has the cross-sectional shape shown in Figure 2), the inner diameter (e) of the opening (8a) is 100 pm, and the conical part (8c) (D+i-1
is 150pm, and the depth of the pinhole (8d) is 5μ.
The inner diameter (p) of the opening (8b) is set to 0.25 μm. The X-ray resist film (9) uses a 0M8 (negative) resist and is coated with a 5000% film thickness of AK. The mask (2) and the shutter (31 are made of the same material; the mask support film is made of electrified silicon 5), and the Xla absorber is made of gold. The diameter of the mark (10a) on the mask (2) is <0.25 μm (which is the same as the diameter of the opening (sb) of the through hole (81) of the semiconductor substrate (1), and the X-ray generating part (4) is 1) The series of X-ray spectra (wavelength 7.131)
)t-use. When alignment was performed while maintaining the distance between the semiconductor substrate (1) and the mask (2) at 10 μm, the X-ray detection intensity increased by 7 times in just 1 second, and the mask alignment was completed at that point. . Thereafter, the shutter (3) was removed from the exposure system, and pattern exposure was performed with an exposure amount of 601) J/-.

When the resist pattern after development was measured using a light wave interference type coordinate measuring machine, the one position alignment accuracy was ±0.05 μm or less.

(G1. Effects of the invention The present invention provides mask matching that is superior to the X-ray transfer method.

Since the transfer can be performed using X-rays from the X-ray generating section, highly accurate positioning is possible in a short time. Furthermore, there is no need to provide a complicated optical system for alignment, resulting in a simpler apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of one embodiment of the device of the present invention, FIG. 2 is a partial cross-sectional view of a semiconductor substrate, and the third factor is a waveform diagram of the senna output. (1)...Semiconductor substrate, (2)-X-ray transfer mask.

Claims (1)

[Claims] (1) The opening on the back side of the substrate, which is used as an alignment mark, has a plurality of through holes that are larger than those on the front side of the substrate,
A semiconductor substrate having an X-ray resist film attached to the surface of the substrate, an X-ray transfer mask having a mask pattern disposed above the semiconductor substrate and including an alignment mark corresponding to the through hole, and the alignment mark. a shutter having an opening in a corresponding part so that only the part is irradiated with X-rays; an X-ray generating part disposed above the shutter and irradiating X-rays onto the shutter; and a back surface of the substrate of the semiconductor substrate. an X-ray sensor disposed on a side facing the through hole; a substrate stage on which the semiconductor substrate is placed and moves the semiconductor substrate in a surface direction; and an X-ray sensor output that receives the X-ray sensor output. An X-ray mask transfer apparatus comprising: a controller that controls the position of the substrate stage based on the above.