JPH05190650A - Semiconductor substrate - Google Patents

Abstract

PURPOSE:To prevent a foreign matter from affecting a following process for bad even if it is produced by rubbing between a substrate contact part of a substrate carrier device and a semiconductor substrate when the semiconductor substrate is carried by a substrate carrier device by providing a recessed part to a rear of the semiconductor substrate. CONSTITUTION:Both sides of a semiconductor substrate 10 are finished flat. A rear 12 is provided with disc-like recessed parts 14 on the same circumference, desirably at specified three positions to an orientation flat 18 of the semiconductor substrate 10. Thereby, even if the semiconductor substrate 10 and the substrate carrier device are rubbed and a foreign matter is produced, the foreign matter gathers in a recessed part 14 and does not attach to a front or a rear of the semiconductor substrate. Therefore, a foreign matter does not affect smoothness of the semiconductor device for bad even if it is mounted on an exposure device and a good pattern can be formed in the semiconductor device.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to improvements in semiconductor substrates.

[0002]

2. Description of the Related Art A conventional semiconductor substrate has both a flat surface and a back surface. When the semiconductor substrate is mechanically transported, the semiconductor substrate is supported and transported by the substrate transport device. In this case, the front surface of the semiconductor substrate on which the semiconductor element is formed is not in contact with the substrate transfer device, and the back surface of the semiconductor substrate on which the semiconductor element is not formed is in contact with the substrate transfer device. The substrate transfer device is provided with a substrate supporting portion such as a convex portion or a pin, and the substrate supporting portion comes into contact with the back surface of the semiconductor substrate.

[0003]

When a semiconductor substrate is transported by the substrate transport device, the substrate contact portion of the substrate transport device and the semiconductor substrate rub against each other. Then, either one (in many cases, the semiconductor substrate) may be scraped, and the scraped fine particles may adhere to the front surface or the back surface of the semiconductor substrate. When such a semiconductor substrate is mounted on, for example, an exposure apparatus, the adhered foreign matter impairs the smoothness of the semiconductor substrate, and as a result, there is a problem in that defocusing occurs during exposure, resulting in defective pattern formation.

Therefore, an object of the present invention is to convey a semiconductor substrate by a substrate transfer device even if the foreign substance is generated due to the rubbing between the substrate contact portion of the substrate transfer device and the semiconductor substrate. The object is to provide a semiconductor substrate that does not adversely affect the process.

[0005]

The above object is achieved by a semiconductor substrate according to the present invention, which is characterized in that it has flat both sides and that a recess is provided in a part of the back surface which comes into contact with the substrate transfer device. can do.

The recess may have any shape that matches the shape of the substrate supporting portion provided on the substrate transfer device.
For example, it may have an annular shape, a circular shape provided at a plurality of locations, a rectangular shape, or the like. The position on the back surface of the semiconductor substrate where the recess is to be formed depends on the position of the substrate supporting portion provided on the substrate transfer device. The depth of the recess depends on the size of foreign matter that can occur and the mechanical strength of the semiconductor substrate,
For example, it can be 2 to 10 μm.

[0007]

In the semiconductor substrate of the present invention, a recess is provided in a part of the back surface which comes into contact with the substrate transfer device. Therefore, a foreign substance generated by rubbing the substrate transfer device and the recessed portion of the semiconductor substrate, for example, by scraping the semiconductor substrate, remains at the bottom of the recessed portion and does not adhere to the front surface or the back surface of the semiconductor substrate. Therefore, it is possible to prevent such foreign matter from adversely affecting the subsequent steps such as the exposure step.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The semiconductor substrate of the present invention will be described below based on embodiments with reference to the drawings.

FIG. 1 is a perspective view of a semiconductor substrate according to the first embodiment of the present invention as viewed from the back side. As the semiconductor substrate 10 whose both surfaces were finished flat, one having a diameter of 200 mm and a thickness of 725 μm was used. Backside 1 of semiconductor substrate 10
In FIG. 2, circular recesses 14 are provided on the same circumference, preferably at three predetermined positions with respect to the orientation flat 18 of the semiconductor substrate 10. The recess 14 had a diameter of 20 mm and a depth of 10 μm. With such a depth, the mechanical strength of the semiconductor substrate is not reduced. In addition, the depth is sufficient compared to the size of the foreign matter.

The recess can be formed by a known method. For example, it can be formed using a grindstone. Alternatively, it can be formed by forming a patterned photoresist on the back surface of the semiconductor substrate and etching the back surface of the semiconductor substrate using a mixed solution of hydrofluoric acid and nitric acid before the wafer process.

A bottom portion 16 of the recess 14 thus formed,
For example, the semiconductor substrate 10 can be transported in a state of being in contact with the substrate supporting portion of the substrate transporting device including three pins.

FIG. 2 is a perspective view of the semiconductor substrate according to the second embodiment of the present invention viewed from the back surface side. The semiconductor substrate used is the same as the semiconductor substrate shown in FIG. An annular recess 24 is provided on the outer periphery of the back surface 12 of the semiconductor substrate 10. The width of the annular recess 24 in the diameter direction is 20 m.
m and the depth was 10 μm. The recess can be formed by the same method as in the first embodiment.

The bottom portion 26 of the recess 24 thus formed is
For example, the semiconductor substrate 10 can be transported in a state of being in contact with the substrate supporting portion of the substrate transportation device including three to four pins. The shape of the recess shown in the second embodiment allows the substrate supporting portion and the back surface of the semiconductor substrate to come into contact with each other without depending on the positional relationship between the semiconductor substrate and the substrate supporting portion of the substrate transfer device, and thus the first embodiment The shape is more preferable than the recess shown in FIG.

Although the semiconductor substrate of the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments. The shape of the recess may be not only circular but also polygonal. Also, when the recess is annular,
It is possible to have not only one but also a plurality of rings, or a part of which may have a discontinuous ring shape. The size and depth of the recess can be appropriately changed depending on the size of the substrate supporting portion of the substrate transfer device, the mechanical strength required for the semiconductor substrate, and the like.

[0015]

Since the semiconductor substrate of the present invention is provided with the concave portion on its back surface, even if the semiconductor substrate and the substrate transfer device are rubbed with each other to generate a foreign substance, the foreign substance remains in the concave portion and the semiconductor substrate Does not adhere to the front or back. Therefore, even when the semiconductor substrate is mounted on, for example, an exposure apparatus, such foreign matter does not adversely affect the smoothness of the semiconductor substrate, and a good pattern can be formed on the semiconductor substrate.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a semiconductor substrate of the present invention.

FIG. 2 is a perspective view showing a second embodiment of the semiconductor substrate of the present invention.

[Explanation of symbols]

 10 Semiconductor Substrate 12 Backside of Semiconductor Substrate 14,24 Recess 16,26 Bottom of Recess 18 Orientation Flat

Claims (1)

[Claims] 1. A semiconductor substrate having flat both sides and having a recessed portion in a part of the back surface which comes into contact with the substrate transfer device.