JPH0546039U - Interlock mechanism - Google Patents

Abstract

(57) [Summary] [Object] The present invention, in single-wafer processing for processing semiconductor wafers one by one to manufacture semiconductors, prevents the wafer from being bent or damaged when clamped and fixed. [Structure] When a wafer 1 is conveyed to a predetermined position, motors 11, 21, 31 operate to move grip portions 13, 23, 33 in a direction in which the wafer 1 is tightened. When the tightening of the wafer is started, an increase in grip pressure is detected by the grip pressure sensors 12, 22, 32. This pressure value is converted into a voltage and input to 14, 24 and 34 comparators. In the comparator, the value of the pressure upper limit register of 15, 25, 35 is compared, and when it exceeds the upper limit value, a stop signal is output to the motor and the motor stops.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an apparatus for holding wafers in a single-wafer processing for manufacturing semiconductors by processing each wafer.

[0002]

[Prior Art]

 In recent years, process lines that process wafers in an ultra-clean environment have been in the spotlight. (NIKKEI MICRODEVICES separate volume No.2 October 1988 p182-p190) It is indispensable to process each wafer in this line (single wafer processing) because the size of ultra-clean space is limited. Has become.

[0003]

[Problems to be solved by the device]

 The above-mentioned prior art does not refer in detail to a method of fixing a wafer when cleaning the wafer. The present invention aims to provide a fixture when the wafer is secured and processed.

[0004]

[Means for Solving the Problems]

 A simple mechanism for achieving the above purpose would be a grip mechanism that holds the wafer. For example, the transferred wafer can be held at three points in the direction parallel to the plane and held so that the wafer does not shake due to external force such as cleaning. However, if too much pressure is applied during gripping, the wafer will bend and it will be damaged.

Therefore, the pressure at the time of gripping the wafer is measured so as not to damage the wafer, and the grip operation is stopped when a certain upper limit value is exceeded.

[0006]

[Action]

 By setting the upper limit value to an appropriate value, all wafers can be gripped with a constant pressure, and unnecessary and non-uniform wafer distortion due to grip pressure can be eliminated. Further, it is possible to prevent the wafer from being bent / damaged due to an excessive grip pressure.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. Reference numeral 1 is a wafer that has been transferred and is in the process of being processed. Reference numerals 13, 23 and 33 are grip portions for holding the wafer 1. Reference numerals 11, 21, 31 are drive motors for moving the grip portion horizontally on the wafer plane. Reference numerals 12, 22, and 32 are pressure sensors that measure how much pressure the grip portion clamps the wafer.

When the wafer is transferred to a predetermined position, the motors 11, 21, 31 operate to move the grip portions 13, 23, 33 in the direction in which the wafer 1 is tightened. When the wafer is tightened, the grip pressure sensor 12, 22, 32 detects an increase in grip pressure. This pressure value is converted into a voltage and input to the comparators 14, 24 and 34. The comparator compares the values of the pressure upper limit value registers of 15, 25, and 35, and when the value exceeds the upper limit value, outputs a stop signal to the motor and stops the motor.

With the above mechanism, the wafer can be always clamped with an appropriate pressure, and the wafer can be prevented from being bent or damaged.

It can also be used as a detection device for the wafer itself. Usually, a photo sensor is used to detect the presence or absence of an object, but the use of a photo sensor is not appropriate due to the glossy surface of the wafer. In addition, because the size of the ultraclean space is limited, it is often difficult to secure space for installing the photosensor. Further, since the photo sensor is not normally acid-resistant, it is not suitable for treating a wafer with a chemical solution. In the device shown in Fig. 1, only 13, 23, 33 can be enclosed in the housing to create an ultra-clean environment (the sensor for 12, 22, 32 is realized by a diaphragm). Can be made as small as possible.

[0011]

[Effect of the device]

 According to the present invention, since the wafer can be clamped by the specified pressure, it is possible to prevent the wafer from being bent or damaged. In addition, it is possible to reduce non-uniform strain that occurs each time the wafer is clamped and fixed.

[Brief description of drawings]

FIG. 1 is a view showing a wafer tightening device according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Wafer, 11, 21, 31 ... Grip drive motor,
12, 22, 32 ... Grip pressure sensor, 13, 23,
33 ... Wafer grip part, 14, 24, 34 ... Comparator, 15, 25, 35 ... Pressure upper limit register.

Claims (1)

[Scope of utility model registration request] 1. A grip mechanism for tightening a wafer, a detector for detecting a pressure for tightening a wafer, a pressure value storage device for storing an upper limit value of the pressure, and an output value of the pressure upper limit value from the detector. An interlock mechanism characterized by stopping the tightening operation of the grip mechanism when a pressure exceeding an upper limit value is detected in a wafer single-wafer processing apparatus comprising: