KR20030090409A - Ion implantation system - Google Patents

Abstract

PURPOSE: An ion injection system is provided to prevent ions from being injected after a wafer falls and make the inside of a process chamber not contaminated by determining whether the wafer falls due to an outside impact or inside movement and by installing an interlock unit for interlocking the operation of an ion injection unit. CONSTITUTION: The ion injection system includes an ion generation block(100a) for abstracting only necessary ions by using ion gas and an ion injection block(100b) for injecting the ions generated from the ion generation block into the wafer(180). An ion injection process is performed in the process chamber(200). The ion injection unit(160) substantially injects ions, installed in the process chamber. A disc(170) is installed in the process chamber. The wafer into which ions are to be injected is disposed in the upper portion of the disc. A driver unit(210) flips up the wafer so that the wafer confronts the ion injection unit. The interlock unit(220) stops the operation of the ion injection unit when the wafer falls during the flip-up operation of the wafer or an abnormal signal is applied to the driver unit.

Description

Ion implantation system

The present invention relates to an ion implantation apparatus, and more particularly to an ion implantation apparatus that can reduce the generation of secondary electrons in the process chamber.

In general, ion implantation in a semiconductor fabrication process is a physical method of adding impurities to impart electrical properties to a silicon wafer, which selectively accelerates the required type of impurity ions by the required amount to selectively select the required depth of the wafer. As much as infusion technology.

The ion implantation method has a smaller thermal diffusion of impurities than the conventional thermal diffusion method, enables a low temperature process, and allows the formation of a doped region without damaging the photoresist. It has a feature that can overcome the limitation, has been widely used in the semiconductor field recently.

1 and 2, a plan view schematically showing a general ion implantation apparatus.

Referring to FIG. 1, the ion supply 11 forms an ion beam in a known manner.

The ion beam formed in the ion supply 11 is accelerated through the ion accelerator 13 and the ion analyzer 15, and only the ions to be ion-implanted on the wafer are extracted from the ion beam containing many kinds of ions.

The extracted ions are injected into the process chamber 20 via the moving passage 17. At this time, before the ions are moved into the process chamber 20, the moving passage 17 calculates the dose of ions and is called a beam gate 19 called Faraday. As the name implies, the beam gate 19 detects and blocks the injection of an ion beam. The ions passing through the beam gate 19 are injected into the wafer 25 placed on the disk 23 from the ion implantation portion 21 in the process chamber 20.

At this time, at the time of ion implantation, the wafer 25 is flipped up by 90 ° with the surface of the disk 23 by the driving unit 30 incorporating the motor, as shown in FIG. 2. Ion implantation is performed from the ion implantation section 21.

However, the conventional ion implantation system has the following problems.

In other words, the conventional ion implantation system is such that the wafer 25 is flipped up to 90 ° with respect to the disk 23 surface, and then an ion implantation process is performed. However, during the process, the flipped-up wafer 25 easily falls to the bottom due to a slight external impact or shaking in the process chamber. At this time, this problem also exists during wafer flip-down after the ion implantation process. As such, when the wafer 25 falls to the bottom of the chamber 20, the ion implantation process may not be performed smoothly, and in severe cases, the wafer may be damaged to contaminate the inside of the chamber.

Accordingly, an object of the present invention is to provide an ion implantation system capable of interlocking the driving of an ion implantation device by detecting a wafer falling from a disk during an ion implantation process.

1 is a view showing a general ion implantation system.

2 is a view for explaining a flip-up operation of the wafer.

3 is a view showing an ion implantation system according to an embodiment of the present invention.

4 is a block diagram illustrating an interlock unit of FIG. 3.

(Explanation of symbols for the main parts of the drawing)

110: ion supply 120: ion accelerator

130: ion analyzer 140: ion passage

210: driver 220: interlock

Other objects and novel features thereof, together with the objects of the present invention, will be apparent from the description and the accompanying drawings.

Among the inventions disclosed herein, an outline of representative features is briefly described as follows.

The ion implantation apparatus of the present invention includes an ion generation block for extracting only ions required by an ion gas, and an ion implantation block for implanting ions generated from the ion generation block into a wafer, wherein the ion implantation block includes: A process chamber in which an implantation process is performed, an ion implantation unit provided in the process chamber to substantially implant ions, a disk provided in the chamber, and a wafer to be implanted with ions thereon, and the wafer A driving unit for flipping up to face the ion implantation unit, and an interlock unit for stopping the operation of the ion implantation unit when the wafer falls to the bottom of the chamber during the flip-up operation of the wafer or when an abnormal signal is applied to the driving unit.

Here, the ion generating block may include an ion supply for decomposing and ionizing an ion gas to generate an ion beam, an ion accelerator for accelerating the ion beam, and an ion analyzer for extracting only necessary ions from the accelerated ion beam from the ion accelerator. Can be.

The driving unit may include a motor operated by a predetermined voltage.

The interlock unit may further include a current measuring unit measuring a current fed back from the process chamber, a voltage measuring unit measuring a voltage applied to a motor in the driving unit, and a current value measured by the current measuring unit. And a control unit for outputting a control signal to stop driving of the ion implantation unit when the voltage is greater than or equal to the predetermined current value or when the transient voltage is measured from the voltage measuring unit.

The ion generation block and the ion implantation block are connected by a moving passage having a beam gate for detecting and extracting an unnecessary ion beam while the dose amount of ions is adjusted.

According to the present invention, according to the present invention, an interlock portion for interlocking the operation of the ion implantation portion is provided by measuring whether or not the wafer has fallen due to external impact or internal shaking during flip up of the wafer. Accordingly, even though the wafer has fallen, it is possible to prevent the ion implantation from being carried out continuously and to prevent contamination in the process chamber.

(Example)

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, embodiments of the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Accordingly, the shape and the like of the elements in the drawings are exaggerated to emphasize a more clear description, and the elements denoted by the same reference numerals in the drawings means the same elements. In addition, where a layer is described as being "on" another layer or semiconductor substrate, a layer may exist in direct contact with the other layer or semiconductor substrate, or a third layer therebetween. Can be done.

3 is a plan view of an ion implantation apparatus according to the present invention.

First, referring to FIG. 3, the ion implantation system of the present invention includes an ion generation block 100a and an ion implantation block 100b.

Here, the ion generation block 100a may include an ion supply unit 110 that generates an ion beam, an ion accelerator 120 that accelerates the ion beam, and an ion analyzer 130 that extracts only necessary ions from the ion beam accelerated from the ion accelerator. Include.

Here, the ion beam generated by the ion supply 110 is obtained by colliding an ion gas such as PH or AsH with electrons, thereby decomposing and ionizing the ion gas.

The ion analyzer 130 extracts only ions to be used for ion implantation in a large amount of ion beams.

On the other hand, the ion implantation block 100b includes a process chamber 200 in which ion implantation proceeds. In the process chamber 200, an ion implantation unit 160 for substantially implanting ions and a disk 170 on which the wafer 180 is seated are disposed. In this case, the disk 170 has a wafer susceptor disposed radially so that several wafers 180 can be placed thereon. In this drawing, it is not shown because it is covered by the wafer 180.

In addition, the ion implantation block 100b may have a driving unit 210 for flipping up or flipping down the wafer 180 in the process chamber 200 and an error occurs during flip-up of the wafer 180, or from the driving unit 210. It includes an interlock unit 220 to stop the operation of the ion implantation unit 160 when the abnormal signal is applied.

The driving unit 210 includes a motor serving as a driving source for flipping up the wafer 180.

Meanwhile, the interlock unit 220 may include a current measuring unit 221 measuring current fed back from the process chamber, a voltage measuring unit 223 measuring a voltage applied to a motor in the driving unit 210, and When the current value measured by the current measuring unit 221 is equal to or greater than or equal to a predetermined current value, or when the transient voltage is measured by the voltage measuring unit 223, the driving of the ion implanter 160 is stopped. The control unit 225 for outputting a signal.

At this time, the ion generation block 100a and the ion implantation block 100b are connected by the movement passage 140, and the dose amount of the injected ions is adjusted in the movement passage 140 to detect whether an unnecessary ion beam enters and The beam gate 150 to extract is provided.

The operation of the ion implantation system of the present invention will be described.

After generating ions in the ion supply 110 of the ion generating block 100a, ions are accelerated from the ion accelerator 120 and the ion analyzer 130, and only the ions to be implanted are extracted. These ions are adjusted in the dose amount in the beam gate 150 of the movement passage 140, and then moved to the ion controller 160.

In this case, when ions are injected from the ion controller 160, a three-phase voltage is applied to the motor of the driver 210, for example. Accordingly, the motor is driven and the wafer 180 is flipped up at an angle that is good for ion implantation, for example, at 90 ° from the disk surface. Here, after the ion implantation is completed, the wafer is flipped down by driving the motor.

In this case, the current measuring unit 221 of the interlock unit 220 measures the current fed back when the motor is driven, and the voltage measuring unit 223 measures the voltage applied to the motor.

In general, when the wafer 180 falls due to an external impact or the like, the feedback current is extremely larger or smaller than the predetermined current value. In addition, when excessive voltage is applied to the motor, since a large current is applied to the wire, it may affect the wafer flip-up. Accordingly, when an abnormality is detected in the current or the voltage by the current measuring unit 221 and the voltage measuring unit 223 of the present embodiment, the controller 225 causes the wafer 180 to fall or an overvoltage is applied to the motor. The sound is sensed and a control signal is output so that the ion implantation unit 160 is interlocked.

Accordingly, it is possible to prevent the ion implantation process from continuing after the wafer falls.

As described in detail above, according to the present invention, according to the present invention, the operation of the ion implantation unit is interlocked by measuring whether or not the wafer has fallen due to external impact or internal shaking during flip-up of the wafer. The interlock part to be installed. Accordingly, even though the wafer has fallen, it is possible to prevent the ion implantation from being carried out continuously and to prevent contamination in the process chamber.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. .

Claims (5)

An ion generation block for extracting only the ions required by the ion gas, and an ion injection block for implanting ions generated from the ion generation block into the wafer, The ion implantation block, A process chamber through which an ion implantation process is performed, An ion implantation unit provided in the process chamber and substantially implanting ions; A disk provided in the chamber and having a wafer on which an ion is to be implanted; A driving unit to flip up the wafer to face the ion implantation unit; And And an interlock portion configured to stop the operation of the ion implantation portion when the wafer falls to the bottom of the chamber during the flip-up operation of the wafer or an abnormal signal is applied to the driving portion. The method of claim 1, The ion generating block, And an ion analyzer for decomposing and ionizing the ion gas to generate an ion beam, and an ion accelerator for accelerating the ion beam and an ion analyzer for extracting only necessary ions from the accelerated ion beam from the ion accelerator. The method of claim 1, And the driving unit comprises a motor operated by a predetermined voltage. The method according to claim 1 or 3, The interlock unit, A current measuring unit measuring a current fed back from the process chamber; A voltage measuring unit measuring a voltage applied to the motor in the driving unit; And a control unit outputting a control signal to stop driving of the ion implantation unit when the current value measured by the current measuring unit is equal to or greater than or equal to a predetermined current value or when a transient voltage is measured from the voltage measuring unit. Ion implantation system. The method of claim 1, further comprising a moving passage having a beam gate that connects the ion generating block and the ion implantation block, adjusts the dose of extracted ions, and detects and extracts unnecessary ion beams. Ion implantation system.