KR20060118747A - Temperature controlling assembly and ion implanter having the same - Google Patents

Abstract

A temperature control assembly and an ion implanting apparatus having the same are provided to prevent contamination of a supporting unit by employing a thermoelement array for cooling the supporting unit. An ion supplying source(202) provides an ion beam. An ion implantation chamber(204) is connected to the ion supplying source and performs an ion implantation on a wafer(W). A supporting unit(110) is formed in the ion implantation chamber and supports the wafer. A thermoelement array(120) is formed on a lower portion of the supporting unit and controls temperature of the supporting unit. A power(130) supplies power to the thermoelement array. A temperature sensor(140) is formed on the supporting unit and detects temperature of the supporting unit. A controller(150) compares the temperature detected in the temperature sensor and pre-set temperature to control the power unit so that the temperature of the supporting unit can be controlled to the pre-set temperature.

Description

Temperature controlling assembly and ion implanter having the same {Temperature controlling assembly and ion implanter having the same}

1 is a schematic cross-sectional view for explaining a temperature control assembly of a wafer support according to the prior art.

Figure 2 is a schematic cross-sectional view for explaining the temperature control assembly of the wafer support according to an embodiment of the present invention.

3 is a schematic cross-sectional view for explaining an ion implantation apparatus having a temperature control assembly according to another preferred embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: temperature control assembly 110: support

120: thermoelectric element array 130: power supply

140: temperature sensor 150: control unit

200 ion implantation device 202 ion source

204 Ion implantation chamber 210 Ion generator

220: ion extractor 230: polarity converter

240: mass spectrometer 250: accelerator

260 ion deflection meter W wafer

The present invention relates to a temperature control assembly for supporting a wafer and an ion implantation apparatus having the same, and more particularly, to a temperature control assembly for controlling a temperature of the support heated during a process of implanting ions into the wafer. It relates to an ion implantation device having.

In general, a semiconductor device includes a Fab process for forming an electrical circuit on a silicon wafer used as a semiconductor substrate, a process for inspecting electrical characteristics of the semiconductor devices formed in the fab process, and the semiconductor devices are epoxy It is manufactured through a package assembly process for encapsulating and individualizing with resin.

The fab process includes a deposition process for forming a film on a semiconductor substrate, a chemical mechanical polishing process for planarizing the film, a photolithography process for forming a photoresist pattern on the film, and the photoresist pattern. An etching process for forming the film into a pattern having electrical characteristics, an ion implantation process for implanting specific ions into a predetermined region of the semiconductor substrate, a cleaning process for removing impurities on the semiconductor substrate, and the film or pattern Inspection process for inspecting the surface of the formed semiconductor substrate;

The ion implantation process is a process of injecting ionized impurities onto a wafer surface, which is one of the main processes for forming electrical elements of a semiconductor device. The ion implantation process has an advantage of easily adjusting the implantation amount and implantation depth of ions compared to the conventional thermal diffusion process.

The ion implantation apparatus includes an ion generator for ionizing a source gas, an ion extractor for extracting ions provided from the ion generator, a mass spectrometer for sorting specific ions among the ions, and a predetermined energy Accelerated to form an ion beam, an ion deflector for adjusting the traveling direction of the ion beam to scan the surface of the wafer disposed in the ion implantation chamber, a support for supporting the wafer, and the like. .

1 is a schematic cross-sectional view for explaining a temperature control assembly of a wafer support according to the prior art.

Referring to FIG. 1, an electrostatic chuck is used as the support 10 supporting the wafer W. As shown in FIG. In the ion implantation process, the temperature of the support 10 as well as the wafer W increases. Therefore, the cooling plate 20 is provided below the support part 10. A cooling line 30 is provided inside the cooling plate 20, and the support unit 10 is cooled by circulating DI water along the cooling line 30 in a chiller 40.

In FIG. 1, the area indicated by the dotted line is a space in a vacuum state.

There are several problems with such temperature control assemblies.

First, there is a problem that the pure water leaks due to corrosion of the cooling line 30 to contaminate the support 10. Therefore, the expensive support 10 must be replaced frequently, which delays the semiconductor manufacturing process and increases the cost.

Next, when the chiller 40 is used continuously, there is a problem that the performance is lowered and the flow rate of the pure water supplied to the cooling line 30 is reduced, thereby reducing the cooling efficiency.

In addition, since the cooling line 30 is installed from the chiller 40 located in the atmospheric pressure space to the cooling plate 20 located in the vacuum space, vacuum leakage occurs at the site where the cooling line 30 is installed. There is a problem.

An object of the present invention for solving the above problems is to provide a temperature control assembly capable of electronically controlling the temperature of the wafer support.

Another object of the present invention for solving the above problems is to provide an ion implantation device having the temperature control assembly.

According to a preferred embodiment of the present invention for achieving the object of the present invention, the temperature control assembly is a wafer polishing apparatus is provided in the lower portion of the support for supporting the wafer, the thermoelectric element array for adjusting the temperature of the support And a power supply unit connected to the thermoelectric element array and supplying power to the thermoelectric element array.

The temperature control assembly is provided in the support part and compares a temperature sensor detecting a temperature of the support part with a temperature detected by the temperature sensor and a preset temperature to control the power supply unit so that the temperature of the support part approaches the preset temperature. The control unit may further include a.

According to a preferred embodiment of the present invention for achieving another object of the present invention, the ion implantation device is an ion source for providing an ion beam, the ion source is connected to, the ion for performing the ion implantation process of the wafer A power supply is provided in an injection chamber, an ion implantation chamber, a support part for supporting the wafer, a support part provided below the support part, and a thermoelectric element array and a thermoelectric element for controlling a temperature of the support part. It includes a power supply for.

The ion implantation device is provided in the support part and compares a temperature sensor detecting a temperature of the support part with a temperature detected by the temperature sensor and a preset temperature to control the power supply part so that the temperature of the support part approaches the preset temperature. The control unit may further include a.

According to the present invention configured as described above it is possible to prevent the contamination of the support by cooling the support using a thermoelectric element, it is possible to improve the temperature uniformity of the support.

Hereinafter, a temperature control assembly and an ion implantation apparatus having the same according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a schematic cross-sectional view for explaining the temperature control assembly of the wafer support according to an embodiment of the present invention.

Referring to FIG. 2, the temperature control assembly 100 includes a thermoelectric element array 120, a power supply unit 130, a temperature sensor 140, and a controller 150. For reference, the region indicated by the dotted line in FIG. 2 is a vacuum space.

The temperature control assembly 100 adjusts the temperature of the support 110 supporting the wafer W while injecting ionized impurities into the wafer W surface. Specifically, since the impurity impinges on the surface of the wafer (W) at a high speed, the temperature of the wafer (W) and the support part (110) rises, thereby cooling the support part (110) by using the temperature control assembly (100).

The support 110 is preferably an electrostatic chuck capable of fixing the wafer W using an electrostatic force.

The thermoelectric element array 120 is provided below the support 110 and cools the support 110 by a power applied from the outside. The thermoelectric element array 120 is composed of a plurality of thermoelectric elements that provide cooling heat at different temperatures.

Typical thermoelectric devices include thermistors, which are devices that use large changes in electrical resistance, devices using the Seebeck effect, which are electromotive forces generated by temperature differences, and the Peltier effect, which is a phenomenon in which heat is absorbed (or generated) by current. Peltier device which is an element using an effect).

The thermoelectric element used in the temperature control assembly 100 is a Peltier element using the Peltier effect. The Peltier effect connects two kinds of metal tips, and when current flows therein, one terminal absorbs heat in the current direction. The other terminal generates heat. By using semiconductors such as bismuth (Bi) and tellurium (Te), which have different electric conduction methods, instead of the two kinds of metals, a Peltier device having an efficient endothermic and exothermic effect can be obtained. It is possible to switch between endothermic and exothermic according to the current direction, and the endothermic and exothermic amount is adjusted according to the current amount.

In detail, the thermoelectric element is generally composed of an n-type semiconductor and a p-type semiconductor. When the power is supplied, endothermic occurs in the n-type semiconductor and heat is generated in the p-type semiconductor. The object can be heated and cooled accordingly. In addition, the thermoelectric element has a heat generation amount and endothermic amount change according to the magnitude of the applied voltage. When the temperature before the power is supplied is referred to as a reference temperature, when more power is supplied, the n-type semiconductor and p The heat generation and endotherm generated in the type semiconductor become larger in proportion to the current. However, the thermoelectric element has a maximum temperature difference according to its intrinsic properties, and no matter how much current is applied, the temperature difference between the heat absorbing portion and the heat generating portion of the thermoelectric element does not exceed the maximum temperature difference.

When the support 110 is cooled using a thermoelectric element as in the present invention, the n-type semiconductor of the thermoelectric element is directed toward the support 110 to cool the support 110. That is, the thermoelectric element is disposed such that the n-type semiconductor of the thermoelectric element faces upward and the p-type semiconductor faces downward.

The power supply unit 130 is connected to the thermoelectric element array 120 to supply power. The thermoelectric element array 120 is composed of a plurality of thermoelectric elements, each of the thermoelectric elements are individually connected to the power supply unit 130. That is, the number of the thermoelectric elements and the number of the power supply units 130 are the same. Therefore, the thermoelectric elements can be individually cooled.

The temperature sensor 140 is provided inside the support 110 to measure the temperature of the support 110. The temperature sensor 140 measures the temperature of the support 110 heated by the ion implantation process and the temperature of the support 110 cooled by the thermoelectric element array 120.

The temperature sensor 140 is provided in plurality in order to measure the temperature according to each portion of the support 110, respectively. Therefore, the temperature sensor 140 is provided evenly distributed on the support 110. The temperature sensor 140 may be disposed in a concentric shape with respect to the center of the support 110.

The control unit 150 is provided to be connected to the temperature sensor 140 and the power supply unit 130, and compares the temperature detected by the temperature sensors 140 with a preset temperature of each portion of the support unit 110. Each of the power supply units 130 is controlled such that the temperature approaches the set temperature. That is, the temperature controller 150 controls the power supply unit 130 so that the support 110 is cooled to a predetermined temperature when the temperature of the support 110 rises and cooling is required.

In detail, when the support 110 is cooled, the temperature controller 150 receives a temperature detected by the temperature sensors 140, and compares the received temperature with a preset temperature. As a result of the comparison, at a portion where the input temperature is detected to be higher than a preset temperature, a signal for turning on the power of the thermoelectric element located below the portion is output or more power is supplied to the thermoelectric element. Outputs a signal to enable In addition, at a portion where the input temperature is detected to be lower than a preset temperature, a signal for outputting a power to turn off the power of the thermoelectric element positioned below the portion or outputting a smaller power to the thermoelectric element is provided. Output the signal.

As described above, the support 110 is provided with a plurality of temperature sensors 140, and the control unit 110 is individually controlled based on the temperature detected by the temperature sensor 140. Can be cooled. In addition, the temperature of the entire support unit 110 can be maintained uniformly.

3 is a schematic cross-sectional view for explaining an ion implantation apparatus having a temperature control assembly according to another preferred embodiment of the present invention.

Referring to FIG. 3, the ion implantation apparatus 200 is largely comprised of an ion source 202, an ion implantation chamber 204, a support 110, and a temperature control assembly 100.

The ion source 202 is provided to provide an ion beam, from the ion generator 210 for generating ions from the source gas, the ion extractor 220 for extracting the ion beam from the ion generator 210, the ion extractor 220 Adjusting the focus of the ion beam, the polarity converter 230 for converting the polarity of the ion beam from positive to negative, the mass spectrometer 240 for selecting specific ions from the negative ion beam, the accelerator 250 for accelerating and converting the polarity of the ion beam A focusing magnet (not shown), an ion deflector 260 for adjusting the direction of the ion beam, an ion current measuring unit (not shown) for measuring the ion current of the ion beam, and the like.

The ion generator 210 is an arc discharge type including an arc chamber, a filament, and the like, and generates ions using a collision between hot electrons provided from the filament and a source gas. In addition, ion generators such as a radio frequency type duoplasmatron, a cold cathode type, a sputter type, a penning ionization type, and the like may be used.

The polarity converter 230 includes a solid magnesium and a heater used as an electron donating material. A high heat of about 450 ° C. is provided to the solid magnesium from the heater, and gaseous magnesium molecules are released from the solid magnesium to collide with the extracted ion beam. By the collision of the magnesium molecule with the ion beam, the ion beam obtains electrons from the magnesium molecule and is converted into an ion beam having negative properties.

As described above, the ion beam having negative properties is provided to the accelerator by selecting only specific ions from the mass spectrometer 240.

Although not shown in detail, the accelerator 250 includes a first accelerator and a second accelerator. A stripper is provided between the first accelerator and the second accelerator to convert the negative ion beam into a positive ion beam. That is, the negative ion beam accelerated by the first acceleration unit is converted into a positive ion beam by the stripper and accelerated again by the second acceleration unit. A high voltage of several thousand to several mega volts is applied to the stripper, and nitrogen or argon gas may be used as the stripping gas to change the polarity.

The positive ion beam accelerated by the accelerator 250 is focused to the focusing magnet through the focusing magnet, and the traveling direction is adjusted by the ion deflector 260 to be provided to the wafer 10. At this time, the ion deflector 260 adjusts the traveling direction of the ion beam so that the ion beam scans the wafer 10.

When converted to a positive ion beam by a stripper, the positive ion beam contains ions having various energy levels. The ion source further includes an ion filter (not shown) for selecting ions having a specific energy from among ions having various energy levels included in the positive ion beam.

Although not shown, the ion current measuring unit is disposed between the mass spectrometer and the accelerator to measure the ion current of the negative ion beam and between the accelerator and the ion implantation chamber to measure the ion current of the positive ion beam. For a second Faraday system.

The ion implantation chamber 204 is connected to the ion source and performs an ion implantation process of a wafer. Inside the ion implantation chamber 204, a support 110 supporting the wafer W to be ion implanted, a temperature control assembly 100, and a driver 270 for controlling the temperature of the support 110 are provided. .

Description of the support 110 is the same as the description of the temperature control assembly according to the embodiment shown in FIG. In addition, since the traveling direction of the ion beam is a horizontal direction, the support 110 preferably supports the wafer W such that the wafer W has a predetermined inclination angle with respect to the traveling direction of the ion beam. The support 110 preferably supports the wafer W such that an incident angle of the ion beam is about 83 °.

Since the description of the temperature control assembly 100 is the same as the above embodiment, it will be omitted.

The driving unit 270 is connected to the lower portion of the support 110, and rotates the support 110 with the central axis of the support 110 as the rotation axis. The drive unit 270 preferably uses a step motor to rotate the support 110 at a constant speed.

As described above, the temperature control assembly and the ion implantation apparatus having the same according to the preferred embodiment of the present invention cools the support for supporting the wafer using a plurality of thermoelectric elements. Therefore, unlike cooling using a cooling line that circulates pure water, corrosion of the line and contamination of the support part by the pure water are prevented. In addition, it is possible to easily adjust the degree of cooling of the support by adjusting each power supplied to the plurality of thermoelectric elements. Therefore, the overall temperature of the support can be kept uniform.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (6)

A thermoelectric element array disposed under the support for supporting the wafer, the thermoelectric element adjusting the temperature of the support; And And a power supply unit connected to the thermoelectric element array and supplying power to the thermoelectric element array. The apparatus of claim 1, further comprising: a temperature sensor provided at the support part and detecting a temperature of the support part; And And a controller configured to control the power supply unit to compare the temperature detected by the temperature sensor with a preset temperature so that the temperature of the support part approaches the preset temperature. The temperature control assembly of claim 2, wherein the power supply unit is connected to a plurality of thermoelectric elements constituting the thermoelectric element array, respectively. The temperature control assembly of claim 1, wherein the thermoelectric element array cools the support. An ion source for providing an ion beam; An ion implantation chamber connected to the ion source and configured to perform an ion implantation process of a wafer; And A support part provided in the ion implantation chamber and supporting the wafer; A thermoelectric element array disposed below the support and configured to adjust a temperature of the support; And And a power supply unit for supplying power to the thermoelectric element. The apparatus of claim 5, further comprising: a temperature sensor provided at the support part and detecting a temperature of the support part; And And a controller configured to control the power supply unit to compare the temperature detected by the temperature sensor with a preset temperature so that the temperature of the support part approaches the preset temperature.

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