KR200159282Y1 - Ion implanter having hard bake oven - Google Patents

Abstract

The present invention relates to an ion implantation device incorporating a hard bake oven for preventing burning or outgassing of the resist formed on the surface of a wafer. It aims to actively respond to changing conditions, reduce the number of wafer movements, reduce particle formation, and provide a cooling chamber to reduce the cooling time of the wafer. Is an ion implantation apparatus for a process of accelerating into a wafer, in order to cure the photoresist after applying a liquid resist on the wafer 8 to form an appropriate pattern on the wafer 8. Bake oven chamber 6 to bake, and bake in the bake oven chamber 6 A cooling chamber (7) for reducing the temperature of the wafer completing the process to provide a hard bake ion implantation apparatus with a built-in oven, characterized in that it can actively cope with the respective process conditions change by device.

Description

Ion implanter with hard bake oven

The present invention relates to an ion implantation apparatus for injecting trivalent or pentavalent impurities by applying electrical energy in a semiconductor manufacturing process after forming a pattern having a desired shape on a surface of a wafer with pores, and more specifically, a wafer. The present invention relates to an ion implantation device incorporating a hard bake oven for preventing burning or outgassing of a photoresist formed on the surface of a film.

In general, the ion implantation method used in the semiconductor manufacturing process refers to a process of accelerating ions of impurity atoms into an electric field into a target (wafer) in order to cope with the impurity doping process of the semiconductor device by high temperature diffusion.

In this ion implantation process, the ion beam is accelerated from 10 to 500KeV to filter out only certain ions from the mass separation magnet, and the specific ions are injected into the wafer through a focus regulator and collide with silicon atoms to lose energy. Through the targets. The distribution of ions implanted in the target is a function of the implantation energy of the ions and the target structure. The distribution of ions implanted in the amorphous target is almost Gaussian, and when implanted into a single crystal, the momentum of implanted ions The crystallinity of the crystal is broken and becomes amorphous. Therefore, after ion implantation, the amorphous silicon single crystal must be recrystallized by heat treatment of 800 ° C. or higher, and the implanted impurities must be placed in the substitution type site of the silicon crystal.

This ion implantation process can precisely control the implantation amount of the impurities, control the distribution of implanted ions, reduce side spreading phenomenon and improve the uniformity of impurities in the wafer compared to the high temperature diffusion process. There is this.

However, in the ion implantation process, it is important to note that the control of the charging problem due to the emission of secondary electrons during ion implantation, the channeling phenomenon due to the crystal lattice donation of the target, and the crystal bonding generated during the recrystallization of the amorphous crystals are controlled. very important.

In addition, when the ion implanter contains boron (B) for the acceptor-type impurity source and phosphorus (P) and arsenic (As) as the donor-type aliquots, these ions may be BF ₃ , PH ₃ , or AsH _3. Produced by ionizing gases.

On the other hand, the device used for the ion implantation should be called a charged particle accelerator in terms of its configuration, but after ionizing the element to be implanted, it accelerates the energy required by the electromagnetic field and injects it into the target, Electrical resistance or hardness, etc.), such an apparatus was originally used for the manufacture of semiconductor accelerators, and the semiconductor process was used to control the threshold voltage of MOS transistors in the early 70's. It was the beginning of commercialization.

Such ion implantation devices are classified by maximum energy and maximum ion current, and are classified into small current devices, medium current devices and large current devices based on the maximum beam current of the device, and also low energy based on the maximum energy of the device. Also referred to as a device, a high energy device.

The midstream device has a maximum beam current up to 5mA, the beam energy is up to 200KeV or more devices, the large current device has a maximum beam current of more than 5mA devices, the high-energy device has a maximum energy of more than 200KeV, MeV class devices are also produced. Such ion implantation apparatuses are classified according to the required ion implantation depth, implantation amount, and precision.

Looking at the configuration of such an ion implantation device, first, the ion source to make the desired ions, a beam line system for transporting the ions to the target, and the end station portion for carrying out the ion implantation process to carry the target, the ion beam is generated in the air A vacuum system is necessary because the production and transfer of all ions and the like must be performed in a vacuum, and thus a vacuum pump is absolutely necessary to generate the vacuum.

In addition, it is common to have a mass spectrometer that selects the ions needed from the various ions generated by the ion source. The acceleration to the required energy is performed before and after the mass spectrometry. It is divided into acceleration types. In addition, a method for uniformly injecting an ion beam into a target includes a scan type and a mechanical scan by moving both sides, such as stopping the wafer to burn the ion beam, fixing the ion beam, and mechanically moving the wafer. Type, hybrid scan type.

The attached FIG. 4 shows various components provided in the end station part of the above-described ion thrombosis device, and as shown, the end station part has a flat aligner for aligning the wafer on a flat table 10 in a predetermined direction. In addition, a load chamber 3, a dummy chamber 4 for adjusting a certain quantity of wafers, and a process chamber 5 are additionally provided in the end station part.

However, prior to the ion implantation process by the conventional ion implantation apparatus described above, there is a process of forming an appropriate pattern on the wafer, which exposes the pantone-shaped portion after undergoing a soft baking process after applying a photoresist on the wafer. After the hard baking process, it is immersed in a developing solution to form a pattern. The double baking process uses a bake oven, and the bake oven device is separated from the ion implantation device and separated from each other. By performing the baking operation by the equipment and a separate process, an interval between the two processes is generated, and since the oven apparatus does not have a cooling system, the baking completed wafer is cooled by a natural method for cooling by about 30 minutes. Due to this delay, wafer transfer can also be done directly by the operator. Particles are generated by workers, and furthermore, since the baking process proceeds at high pressure (120-180 ° C.) and for a long time (30 minutes to 1 hour) at atmospheric pressure, damage to the device and photoridges There has been a problem that the device may be defective or contaminated due to outgassing or burning of the test.

Accordingly, the present invention has been made to solve the above-mentioned problems, and by installing the hard baking process in an ion implantation apparatus, it is possible to actively cope with changes in process conditions for each device, and to reduce the number of wafer movements and particles. It is aimed at reducing the formation and also providing a cooling chamber to reduce the cooling time of the wafer.

1 is a view schematically showing the structure of an ion implantation apparatus according to the present invention.

2 is a cross-sectional view of a bake chamber mounted in an ion implantation apparatus in accordance with the present invention.

3 is a cross-sectional view of a cooling chamber mounted in an ion implantation apparatus in accordance with the present invention.

* Explanation of symbols for main parts of the drawings

1: Table 2: Flat Aligner

3: load chamber 4: dummy chamber

5: process chamber 6: bake chamber

7: cooling chamber 8: wafer

9: heating lamp 10, 14: pedestal

11 quartz window 12 carrier gas introduction tube

13: Rough pump 15: Clean nitrogen introduction tube

16: nitrogen filter

In order to achieve this object, the present invention is an ion implantation apparatus for a process of accelerating ions of impurity atoms into an electric field into a wafer,

After the liquid photoresist is applied on the wafer to form a proper pattern on the wafer, the hard bake oven chamber is baked to cure the photoresist, and the temperature of the wafer after the baking process is completed in the bake oven chamber. The present invention provides an ion implantation apparatus including a hard bake oven, which includes a cooling chamber for reducing and actively coping with changes in process conditions for each device.

In the bake chamber, a heating lamp for heating the wafer is arranged on the bottom of the chamber where the wafer is placed, and is separated and sealed by a quartz window.

In addition, it is preferable that a carrier gas introduction tube is arranged at a rear portion of the heating lamp so that an inert gas is provided in a sealed space in which the heating lamp is installed.

In addition, the inert gas is preferably argon (Ar).

Furthermore, the bake chamber is provided with a rough pump for removing out gas generated from the wafer during the baking process, and the inside of the chamber is preferably in a vacuum state.

The lower end of the cooling chamber has a pedestal to place the wafer after the baking process, the lower support portion of the pedestal so that the cooling water flows into the hollow shape to cool the back of the wafer, the upper end of the chamber clean nitrogen flows in Preferably, an introduction tube is provided to cool the upper surface of the wafer.

In addition, it is preferable that a nitrogen filter is installed between the introduction tube through which the clean nitrogen flows and the wafer.

EXAMPLE

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view schematically showing the structure of the ion implantation apparatus according to the present invention, FIG. 2 is a cross-sectional view of the baking chamber mounted in the ion implantation apparatus according to the present invention, and FIG. 3 is mounted in the ion implantation apparatus according to the present invention Section of the cooling chamber.

1 is a flat aligner (2), a load chamber (3) for aligning a wafer in a predetermined direction on a flat table (1) in an end station of the ion implantation apparatus according to the present invention. In addition to the dummy chamber 4 and the process chamber 5 to match a certain quantity of wafers, a baking chamber 6 and a cooling chamber 7 are additionally provided. Therefore, according to the present invention, the end station part can be processed in a series of processes from the baking process of the wafer to the cooling and ion implantation after the baking process.

On the other hand, the bake chamber 6 added in the ion implantation apparatus according to the present invention is a place for processing the hard baking process of the wafer 8, as shown in FIG. 2, in the bake chamber 6 It is possible to perform metal heating by using the lamp 9 as a heating device. In this configuration, a pedestal 10 is placed on the lower end of the chamber 6 to place the wafer 8 thereon, and a heating lamp 9 is arranged on the top of the pedestal 10 to arrange the quartz window 11. It is sealed by. In addition, a carrier gas introduction pipe 12 is arranged at a rear portion of the heating lamp 9 to provide argon, which is an inert gas, in a sealed space in which the heating lamp 9 is installed, thereby maximizing heating efficiency. Moreover, the rough pump 13 is installed in the chamber 6 to remove the outgas generated from the wafer 8 during the baking process, so that the time is more than 30 minutes at a temperature of 120 ° C. or higher based on the existing 25 sheets. Although it takes, but in the above method takes about 20 ~ 30 seconds per sheet, the temperature inside the chamber 6 is vacuumed so as to obtain the same efficiency even in a lower state than the conventional atmospheric pressure process.

Therefore, when the baking operation is performed by the above method, a time reduction effect of about 15 to 20 minutes can be obtained, and since the baking operation is performed at a low temperature, damage of the wafer can be reduced.

3 shows a cross-sectional view of a cooling chamber 7 according to the present invention, where the cooling chamber 7 cools the wafer 8 from which the process has been completed from the bake chamber 6 for the next ion implantation process. As such, since the wafer 8 processed in the baking chamber 6 is typically heated to 120 ° C. or more, the ion implantation process is impossible in this state, and thus the wafer 8 is removed from the cooling chamber 7. Cool down to an appropriate level.

At the lower end of the cooling chamber 7, there is a pedestal 14 on which the wafer 8 after the baking process is placed. The lower support of the pedestal 14 has a hollow shape so that the cooling water flows into the wafer ( The rear surface of 8) is cooled, and clean nitrogen is injected into the upper end of the chamber 7 to cool the upper surface of the wafer 8. In addition, since the nitrogen filter 16 is provided between the introduction tube 15 and the wafer 8 into which the clean nitrogen flows in, the wafer 8 is cooled by clean nitrogen, and the wafer 8 by nitrogen is supplied. To prevent contamination.

As described above, according to the present invention, by reconfiguring the existing binary ion implantation device and the bake oven device into one system, it is possible to reduce the installation cost and line space, and to reduce the process time by installing the cooling device. Not only can it be reduced, but by maintaining the bake chamber in a vacuum and using a heating lamp, it is possible to expect early development of next-generation devices by shortening process time and reducing wafer damage.

Although the present invention has been illustrated and described with respect to certain preferred embodiments, the present invention is not limited to the above-described embodiments, and the present invention without departing from the gist of the invention as claimed in the utility model registration claims. Anyone skilled in the art will be able to implement various changes.

Claims (7)

An ion implantation apparatus for a process of accelerating ions of impurity atoms into an electric field into a wafer, wherein the photoresist is cured after applying a liquid photoresist on the wafer to form an appropriate pattern on the wafer. A hard bake oven comprising a hard bake oven chamber for baking and a cooling chamber for reducing the temperature of the wafer after the baking process in the bake oven chamber, to actively cope with changes in process conditions for each device. Ion implantation device with built-in. The hard bake according to claim 1, wherein the bake chamber has a pedestal installed at a lower end of the chamber, on which a wafer is placed, and a heat lamp for heating the wafer at an upper part thereof, the hard bake being separated and sealed by a quartz window. Ion implanter with oven. The ion implantation apparatus according to claim 1 or 2, wherein a carrier gas introduction tube is arranged at a rear portion of the heating lamp so that an inert gas is provided in a sealed space in which the heating lamp is installed. . The ion implantation apparatus incorporating the hard bake oven according to claim 3, wherein the inert gas is argon (Ar). The hard bake oven according to claim 1 or 2, wherein the bake chamber is provided with a rough pump for removing the outgas generated from the wafer during the baking process, and the inside of the chamber is maintained in a vacuum state. Ion implantation device with built-in. According to claim 1, The lower end of the inside of the cooling chamber has a pedestal for placing the wafer after the baking process, the lower support portion of the pedestal so that the coolant flows into the hollow shape to cool the back surface of the wafer, An ion implantation apparatus having a hard bake oven, wherein an introduction tube is provided at an upper end thereof to cool the upper surface of the wafer. 7. The ion implantation apparatus of claim 6, wherein a nitrogen filter is installed between the introduction tube into which the clean nitrogen flows and the wafer.