JP2000193425A - Measuring method for semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a measuring error and accurately measure by respectively and coaxially rotating an upper measuring and lower measuring parts passing a measured object rotated between both parts. SOLUTION: A pair of an upper measuring part 1 and lower measuring part 2 are relatively placed and respectively irradiated with a semiconductor laser beam in a mutual inside direction of them. Also, a rotating means is placed in the upper part 1 and lower part 2 to rotate them in the same direction or an opposite direction. Then, a semiconductor wafer W being a measured object is rotated with a mounting holder at a constant speed in a horizontal direction. The wafer W is moved in a constant direction and passed between both semiconductor laser beams of the part 1 and part 2. Thereby, as an average value of a measuring spot is expressed, an error can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a thickness, a surface roughness, a flatness, and the like of a semiconductor wafer which is a substrate in a manufacturing process of an ultra LSI or the like after grinding or polishing. .

[0002]

BACKGROUND OF THE INVENTION Semiconductor wafers of this kind according to the present invention are:
It is used in electronic devices such as computers and integrated circuits such as OA devices, and its development is progressing day by day. There has been a demand for larger diameter and higher ultra-high precision quality from the viewpoint of yield.

In addition, these semiconductor wafer devices are:
With the increase in density and the degree of integration, mass production of ultra LSIs (ULSI) of 64 megabytes or more has begun, and in recent years, ultra LSIs of 256 megabytes or 1 gigabyte, etc.
Is shifting to the age of.

[0004] In these circumstances, the diameter has been further increased from the viewpoint of productivity, and mass production of 12-inch semiconductor wafers has already started, and furthermore, 16-inch semiconductor wafers have been prototyped. Yes, and ultra-high-precision quality is required from the viewpoint of yield, and ultra-high-precision parallel processing of both surfaces of a semiconductor wafer after slicing of a silicon ingot, or ultra-high-precision flat processing of each surface Is essential.

[0005]

2. Description of the Related Art Conventionally, a measuring apparatus using a semiconductor laser for measuring a semiconductor wafer of this kind after grinding and polishing with a grinding machine, a lapping machine, a polishing machine or the like irradiates a laser beam and irradiates the reflected laser beam. It was measured and measured by the optical triangular distance measurement method.

[0006]

However, the diameter of the spot measured by the semiconductor laser is several tens of microns. However, if there is a minute inclination or minute irregularities in the range of the spot diameter, an error occurs in the measurement of the average value. I was

[0007]

In view of the above-mentioned problems, as a result of diligent studies, an upper measuring section and a lower measuring section are vertically arranged using a non-contact automatic measuring apparatus using a semiconductor laser beam. In addition, the upper measuring unit and the lower measuring unit are coaxially rotated, respectively, and the semiconductor wafer to be measured is rotated and passed between the upper measuring unit and the lower measuring unit for measurement.

Accordingly, an object of the present invention is to provide a measurement method for accurately measuring the average value of measurement spots by reducing the measurement error of a semiconductor wafer requiring ultra-high accuracy. is there.

[0009]

According to the present invention, an upper measuring section and a lower measuring section are disposed vertically facing each other, and measurement is performed while rotating the upper measuring section and the lower measuring section coaxially. Since the average value appears as a measured value, the error can be further reduced.

[0010]

Next, a semiconductor wafer measuring apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory view for explaining an embodiment of a semiconductor wafer measuring apparatus according to the present invention.

The present invention relates to an apparatus for measuring a thickness, a surface roughness, a flatness, and the like with ultra-high accuracy after grinding or polishing a semiconductor wafer W serving as a substrate in a manufacturing process of a super LSI or the like. The upper measuring unit 1 and the lower measuring unit 2 are vertically arranged using a non-contact automatic measuring device using light rays, and the upper measuring unit 1 and the lower measuring unit 2 are arranged.
Are rotated coaxially, and the semiconductor wafer W as an object to be measured is passed between the upper measuring unit 1 and the lower measuring unit 2 while being rotated for measurement.

That is, the method for measuring a semiconductor wafer W according to the present invention employs a gliding machine, a lapping machine,
It is to measure the semiconductor wafer W after grinding or polishing by a polishing machine without causing an error,
The semiconductor wafer W after the grinding / polishing processing, which is the object to be measured, is mounted on a ring-shaped mounting table 3 that supports a portion to be cut off in a process after the outer peripheral edge.

The upper measuring unit 1 and the lower measuring unit 2 of the non-contact automatic measuring device using a semiconductor laser beam are a pair of devices arranged above and below the semiconductor wafer W. It has a sensor that irradiates and receives reflected light.

Next, the pair of upper measuring section 1 and lower measuring section 2 are relatively arranged, and the semiconductor laser beams are respectively irradiated inwardly from each other.

Further, the upper measuring unit 1 and the lower measuring unit 2 are provided with rotating means (not shown). The rotating means has the upper measuring unit 1 attached to a rotating shaft vertically suspended from above. ,
Attach the lower measuring unit 2 to the rotating shaft erected from below,
They are rotated in the same direction or opposite directions, respectively.

The semiconductor wafer W to be measured is rotated at a constant speed in the horizontal direction together with the mounting table by the mounting table rotating means. 1 passes between the semiconductor laser beams of the lower measuring unit 2 and the lower measuring unit 2.

[0018]

According to the above configuration, the method for measuring a semiconductor wafer according to the present invention performs measurement by rotating the upper measurement unit and the lower measurement unit. The measurement error of a semiconductor wafer for which accuracy is required is further reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining an embodiment of a semiconductor wafer measuring apparatus according to the present invention.

[Explanation of symbols]

 W semiconductor wafer 1 upper measuring unit 2 lower measuring unit 3 mounting table

Claims (1)

[Claims] An upper measuring unit and a lower measuring unit are vertically arranged using a non-contact automatic measuring device using a semiconductor laser beam, and the upper measuring unit and the lower measuring unit are coaxially arranged. A semiconductor wafer as an object to be measured is rotated and passed between an upper measuring part and a lower measuring part for measurement.