KR20010094053A - Tilt angle measuring system of ion implantation apparatus - Google Patents

Abstract

PURPOSE: A system of measuring the tilt angle of a wafer in an ion implanter is provided to exactly measure the tilt angle of a wafer and easily sense an error of the tilt angle. CONSTITUTION: A wafer has a tilt angle by controlling a driving motor in a driving motor controller(200). An encoder(210) measures the tilt angle of the wafer by receiving an electrical signal from the driving motor controller(200). A tilt angle sensor(220) remeasures the tilt angle of the wafer when the measured value is same to a setting value. An inter-rock controller(230) connected to the encoder(210) and the tilt angle sensor(220) stops the processing when the measured and re-measured values are different from the setting value.

Description

Tilt angle measuring system of ion implantation equipment {TILT ANGLE MEASURING SYSTEM OF ION IMPLANTATION APPARATUS}

TECHNICAL FIELD The present invention relates to semiconductor manufacturing equipment, and more particularly, to a system for measuring a tilt angle of a semiconductor wafer in an ion implantation equipment.

The ion implantation process is a process of physically implanting impurity ions onto a semiconductor wafer. The ions accelerated by the electric field enter the semiconductor wafer and are stopped by collisions and interactions with internal atoms. In this case, the distance at which the ions are incident is proportional to the energy for accelerating the ions, so that the ion can be implanted at a desired depth by adjusting the energy.

However, since the semiconductor wafer is a crystalline solid, the internal atoms are arranged in a regular arrangement. In addition, the space between the lattice lines in a specific direction to form a channel. In the ion implantation process, when the accelerated ions are incident through the channel, a channel effect is injected to a depth deeper than the proper incidence distance.

If a channel effect occurs, it is impossible to control the incident range of the implanted impurity ions. To prevent this, the semiconductor wafer is tilted by 7 ° to 8 ° to proceed with the ion implantation process. In this case, if the inclination angle of the semiconductor wafer is incorrectly measured, a channel effect occurs and a defect of the device is caused, thereby requiring an accurate inclination angle measuring system.

1 is a flowchart showing process steps in an inclination angle measuring system of an ion implantation apparatus constructed according to the prior art.

Referring to FIG. 1, a driving motor control unit 100 for adjusting a driving motor for causing a semiconductor wafer to have a predetermined inclination angle is provided. An encoder 110 that receives an electrical signal from the driving motor controller 100 and measures an inclination angle is provided. An interlock control unit 120 connected to the encoder unit 110 is provided. When the measured value output from the encoder unit 110 is not 8 °, a signal is transmitted to the interlock control unit 120 to stop the process.

When the semiconductor wafer is loaded into the process chamber 100, the driving motor is operated to move the semiconductor wafer to have an inclination angle of 8 ° from the initial horizontal position. The driving motor controller 100 transmits an electrical signal according to the movement of the driving motor to the encoder 110. The encoder 110 calculates an inclination angle of the semiconductor wafer by comparing the input signal with an initial value.

When the value output from the encoder 110 is 8 °, the ion implantation process is performed. On the other hand, when the value output from the encoder unit 110 is not 8 °, the encoder signal is transmitted to the interlock controller 120 connected to the encoder unit 110. When the encoder signal is input to the interlock control unit 120, the interlock signal is output to stop the process. However, when the inclination angle of the semiconductor wafer is measured differently due to a malfunction of the encoder unit 110, there is no device capable of detecting the problem, thereby causing a problem that the process proceeds as it is.

The present invention has been proposed to solve the above-mentioned problems, and an object thereof is to provide an inclination angle measuring system capable of accurately measuring an inclination angle of a semiconductor wafer in an ion implantation device and detecting an inclination angle error.

1 is a flow chart showing the process steps in the tilt angle measuring system of the ion implantation equipment according to the prior art.

Figure 2 is a flow chart showing the process steps in the tilt angle measuring system of the ion implantation equipment according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

100, 200: drive motor control unit 110, 210: encoder unit

220: inclination angle sensor 120, 130: interlock control unit

(Configuration)

According to the present invention for achieving the above object, the inclination angle measuring device of the ion implantation device is a drive motor control unit for adjusting the drive motor so that the semiconductor wafer has an inclination angle from the initial horizontal position, the drive motor control unit is connected to the drive motor An encoder unit measuring an inclination angle of the semiconductor wafer by receiving an electrical signal from a control unit; an inclination angle sensor connected to the encoder unit to re-measure the inclination angle of the semiconductor wafer when a value measured by the encoder coincides with a set value; And an interlock control unit connected to the encoder unit and the inclination angle sensor so as to operate when a value different from the set value is measured.

The inclination angle sensor is preferably installed as a contact sensor.

(Example)

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a flowchart showing the process steps in the tilt angle measuring system of the ion implantation apparatus constructed by the embodiment of the present invention.

Referring to FIG. 2, a driving motor controller 200 is connected to a support on which a semiconductor wafer is placed to adjust a driving motor for moving the support. The semiconductor wafer has an inclination angle set by the drive motor controller 200.

The encoder 210 receives an electrical signal from the driving motor controller 200 and measures an inclination angle of the semiconductor wafer. The encoder 210 is input with an initial value indicating an inclination angle of 0 °, which is an initial state, and when an electric signal indicating movement of the driving motor is transmitted, the inclination angle is calculated based on the initial value.

An inclination angle sensor 220 is provided to be connected to the encoder 210 to re-measure the inclination angle measured by the encoder 210. While the encoder unit 210 is an indirect measuring device that measures the tilt angle by detecting the movement of the driving motor, the tilt angle sensor 220 is a device that directly measures the tilt angle of the semiconductor wafer. The inclination angle sensor 220 may be installed as a contact sensor that detects a position by contacting an object to be measured. A contact sensor is installed on a specific position at which the semiconductor wafer has a set tilt angle so that the support can contact the sensor when the semiconductor wafer has a predetermined tilt angle. The sensor then operates to display the tilt angle of the semiconductor wafer.

An interlock controller 230 connected to the encoder 210 and the inclination angle sensor 220 is provided. If the inclination angle measured by the encoder unit 210 does not coincide with the set value, that is, the inclination angle for preventing the channel effect, 8 °, the encoder signal is installed to be transmitted to the interlock controller 230. In addition, even when the inclination angle measured by the inclination angle sensor 220 does not coincide with the set value 8 °, the signal is transmitted to the interlock controller 230. When the input signal is transmitted from the encoder unit 210 and the inclination angle sensor 220 to operate the interlock control unit 230, an interlock signal is output to stop the process. In addition, when the interlock signal is output, an alarm device or the like operates to enable the operator to detect an inclination angle error.

In the operation of the tilt angle measuring system, when the semiconductor wafer is loaded on a support in the process chamber, the semiconductor wafer has a constant tilt angle by the action of the driving motor control unit 200 connected to the support.

Then, the electric signal indicating the movement of the drive motor in the drive motor control unit 200 is transmitted to the encoder (210). The encoder 210 analyzes the electrical signal to digitize the inclination angle of the semiconductor wafer.

When the inclination angle measured by the encoder unit 210 coincides with the set value 8 °, the encoder signal output from the encoder unit 210 is transmitted to the inclination angle sensor 220. When the encoder signal is transmitted to the inclination angle sensor 220, the inclination angle sensor 220 operates. On the other hand, when the inclination angle measured by the encoder unit 210 does not match the set value, the encoder signal is transmitted to the interlock controller 230. When the encoder signal is transmitted to the interlock control unit 230, an interlock signal is output to stop the process.

After the measurement in the encoder unit 210, the inclination angle sensor 220 is moved to the portion to be measured to measure the inclination angle of the semiconductor wafer. When the value measured by the inclination angle sensor 220 coincides with the set value of 8 °, the ion implantation process continues after the inclination angle measurement is finished. On the other hand, when the value measured by the inclination angle sensor 220 does not match the set value, a predetermined signal is transmitted from the inclination angle sensor 220 to the interlock controller 230 and the process is stopped.

According to this invention, the inclination angle of the semiconductor wafer is measured twice in different ways by the encoder unit 210 and the inclination angle sensor 220. In addition, the encoder 210 and the inclination angle sensor 220 are connected to the interlock controller 230, respectively. Therefore, the inclination angle of the semiconductor wafer can be accurately measured, and if an inclination angle error occurs, it can be detected before the ion implantation process starts.

According to the present invention, the inclination angle sensor connected to the interlock control unit is installed so that the inclination angle of the semiconductor wafer measured by the encoder unit is re-measured by the inclination angle sensor. Therefore, it is possible not only to accurately measure the inclination angle but also to prevent the failure of the semiconductor devices due to the inclination angle error.

Claims (2)

A drive motor controller for adjusting the drive motor so that the semiconductor wafer has an inclination angle from an initial horizontal position; An encoder unit connected to the driving motor controller to receive an electrical signal from the driving motor controller to measure an inclination angle of the semiconductor wafer; An inclination angle sensor connected to the encoder and re-measuring the inclination angle of the semiconductor wafer when a value measured by the encoder matches a set value; and And an interlock control unit connected to the encoder unit and the inclination angle sensor to operate when a value different from the set value is measured. The method of claim 1, The inclination angle sensor is an inclination angle measuring system of the ion implantation equipment, characterized in that installed as a contact sensor.