KR20040105455A - Mass analyzer - Google Patents

Abstract

PURPOSE: A mass spectrometer is provided to remove exposure of an analyzer chamber and prevent the lowering of productivity due to contamination by forming grooves and projections corresponding to the grooves on one side and the other side on opposite sides of an inner sidewall of the analyzer chamber, respectively. CONSTITUTION: A mass spectrometer is used for an ion implantation apparatus for semiconductor fabrication. The mass spectrometer includes an analyzer chamber(231), a plurality of electromagnets installed at an outer surface of the analyzer chamber, and a plurality of guides(20) coupled continuously to an inner wall of the analyzer chamber. Each of the guides includes a groove formed on one of opposite sides and a projection corresponding to the groove.

Description

Mass spectrometer {MASS ANALYZER}

The present invention relates to an ion implantation apparatus of a semiconductor manufacturing equipment, and relates to a mass spectrometer having an analyzer chamber through which an ion beam passes.

In recent years, more accurate impurity control is required to cope with higher integration and higher density of semiconductor devices, and furthermore, in terms of mass production technology, improvement in reproducibility and processing capability are required. Among them, ion implantation technology has become more and more important, and has been put into practical use in place of the conventional technology.

In general, the ion implantation process in the semiconductor manufacturing process is a method of injecting impurities into the wafer in order to have the electrical characteristics of the semiconductor, converts the desired type of impurities into the ion beam, then accelerates them to the required amount or depth required It is a process of selectively injecting evenly or only necessary parts onto the phase.

The ion implanter consists of an ion source, an analyzer, a beam accelerator, a focus lens, an electrostatic classifier, and the ion beam emitted from the ion generator removes mass to remove unwanted ions. Pass through the analyzer.

The mass spectrometer functions to pass only a desired ion beam by using different principles of baking effect even if ions having the same energy in the magnetic field have different masses.

The mass spectrometer further includes an analyzer chamber for diffusing an incoming ion beam at a predetermined angle, an electromagnet mounted on an outer wall of the analyzer chamber to form a predetermined magnetic field for separating and selecting only ions required for a process, and the analyzer chamber It consists of guides mounted along the inner wall of the.

The analyzer chamber has an arc shape and an 'L' shaped duct structure, and the guide mounted along the inner wall of the analyzer chamber is in the shape of a cuboid.

The extracted ion beam passes quickly through the beam accelerator and hits the guide of the analyzer chamber. The edges of the guides mounted on the inner wall of the analyzer chamber are in contact with the side of another adjacent guide, but the shape of the guide is Since it is a rectangular parallelepiped, it has a structure that is gradually spaced toward the center of the analyzer chamber.

That is, only a part of the guide and the other guide are structurally contacted (a corner part attached to the inner wall of the analyzer chamber), and a part is mounted as a spaced part.

As a result, the metal component of the inner wall of the analyzer chamber is transferred together with the ion beam to cause contamination, thereby lowering the yield of the product.

In order to solve the problems as described above, the present invention provides a mass spectrometer capable of preventing the transfer of metal components of the analyzer chamber to the wafer together with the ion beam when implanting an ion beam onto the wafer. For that purpose.

1 is a block diagram showing the configuration of a general ion implantation apparatus;

2 is a diagram illustrating an analyzer chamber in which a guide is installed, which is an embodiment of the present invention;

3A is an enlarged plan view of a portion A of FIG. 2 showing an example of a coupling structure of a guide; And,

Figure 3b is a plan view showing another embodiment showing a coupling structure of the guide.

Explanation of symbols on the main parts of the drawings

20, 20 ': Guide 21: Home

22, 22 ': protrusion 23: outer wall

24: inner wall 26: contact surface

221: analyzer chamber 235: chamber body

237 ion inlet 238 ion outlet

The mass spectrometer of the present invention devised to attain the above object includes an analyzer chamber, electromagnets mounted on the outside of the analyzer chamber, and a plurality of guides continuously coupled to the inner wall of the analyzer chamber, wherein Each guide is characterized by having a plurality of line contacts.

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

1 is a block diagram showing the configuration of a general ion implantation apparatus 700 equipped with a mass spectrometer to explain the present invention.

As shown in FIG. 1, the general ion implantation apparatus 700 in which the analyzer chamber of the present invention is used includes an ion source unit 100, a beamline assembly 200, an end station 300, an apparatus driving unit 500, and a mass. It is composed of a central control unit 400 for overall control of the analyzer 700, each part is interconnected by a data line 70 and a control line (80).

The ion source unit 100 is a place where impurities to be injected into a wafer are ionized in a gas state and extracted with an ion beam. The ion generating unit 120 receives ionized impurities from the outside and ionizes them, and the ionized impurities It is composed of an ion extraction unit 140 for supplying a high energy (Energy) to a strong electric field to extract the ion beam moving at a high speed.

The beamline assembly 200 is a place where the ion beam extracted from the ion source unit 100 moves in the direction of the wafer, and separates and selects only the ions necessary for the process among the ions extracted by the ion beam from the ion extraction unit 140. A gate valve installed between the mass spectrometer 230, the ion extracting unit 140, and the mass spectrometer 230 to selectively open and close the ion beam extracted from the ion extracting unit 140 to the mass spectrometer 230. 210, an ion accelerator 250 for accelerating the ion beam separated and selected by the mass spectrometer 230 at a predetermined speed, and a deflection unit 270 for deflecting the accelerated ion beam uniformly on the wafer. do.

The mass spectrometer 230 diffracts the ion beam to a predetermined angle by using a magnetic field and a mass difference between the respective ions, thereby separating and selecting only ions necessary for the process.

An analyzer chamber 231 for diffusing the ion beam extracted and extracted from the ion extraction unit 140 at a predetermined angle, and mounted on one or both sides of the analyzer chamber 231 so as to analyze only the ions required for the process. It consists of an electromagnet (not shown) that forms a magnetic field.

In addition, the end station 300 is a place where a wafer to be ion implanted is mounted, and the wafer moving unit 350 is provided to set the position of the wafer so that the ion beam via the deflection unit 270 is accurately injected to the target point to be injected. do.

On the other hand, the device driver 500 is a place where the ion implantation apparatus 700 can be smoothly driven, the vacuum unit 560 for controlling the vacuum of each part of the ion implantation apparatus 700, and the ion implantation apparatus 700 It is composed of a power supply unit 580 for supplying various levels of voltage for ion decomposition and extraction and acceleration of the.

FIG. 2 is a view illustrating an analyzer chamber in which a guide is installed according to an embodiment of the present invention, and FIG. 3A is an enlarged plan view of part A of FIG. 2 showing an example of a coupling structure of the guide, and FIG. 3B is a view illustrating the coupling structure of the guide. A plan view showing another embodiment.

Referring to FIG. 2, the analyzer chamber 231 used in the mass spectrometer includes a chamber body 235 having an ion inlet 237 and an ion outlet 239, an electromagnet (not shown), a guide 20, 20 ').

The chamber body 235 is an 'L' shaped and arc-shaped duct structure in which a space of a predetermined size is formed so that an ion beam can be passed through the center, and an opening is formed at one end thereof, and an inlet is introduced at the other end thereof. Another opening is formed so that the ion beam can be diffracted at a predetermined angle and flow out to the ion outlet.

The chamber body 235 is made of a metal material of aluminum or stainless steel, the electromagnet is mounted on the outer wall of the chamber body 235. This electromagnet forms a predetermined magnetic field so that only ions necessary for the process can be separated and selected.

The guides 20 and 20 'are mounted along the inner wall of the chamber body 235, and the plurality of guides 20 are installed to face each other.

Referring to FIG. 3A, the guide 20 forms a groove 21 on one surface of both ends, and the protrusion 22 is fitted to the groove 21 on the other surface corresponding to the groove 21. ) Is formed.

As for the guide 20, the part which protrudes about 1/2 of the thickness extends in the longitudinal direction becomes the protrusion 22. As shown in FIG.

In addition, the protrusion 22 is formed on both sides of the guide 20, it is formed to be shifted left and right asymmetrically.

That is, one side (left end on the drawing) of the guide 20 attached to the inner wall of the chamber body 235 extends so that a portion thereof is in contact with the inner wall. The protruding portion has the shape of the protrusion 21, and the non-protruding portion has the groove 21. In addition, a protrusion 22 ′ having the same size as the protrusion 22 is formed on an opposite side (right end on the drawing) of the guide 20, and the protrusion 22 shifts from the protruding position of the protrusion 22. Form ').

Due to the guide 20 having the shape as described above, one surface of the guide 20 has a continuous arrangement in which one surface of the guide 20 'on the other side comes into contact. This is as if the stepped blocks are attached to the inner wall of the analyzer chamber 231 bent and coupled to each other alternately, each of the guides (20, 20 ') are arranged to be twisted at a predetermined angle. Therefore, the contact surfaces between the guides 20 and 20 'have a line contact, and when the ion beam passes, the metal film of the analyzer chamber 231 does not act as a blocking film.

In addition, the shape of the groove 21 and the projections 22, 22 ', as shown in Figure 3b forms a groove 21 having a round in the center of the guide 20, 20' at its center, the other surface The protrusion 22 ′ is formed to correspond to the groove 21.

When the guides 20 and 20 'are mounted to the chamber body 235, both ends of the guides 20 and 20' have a contact surface 25 between the outer wall 23 and the inner wall 24 to which they face. It is preferable to form.

Forming to have the contact surface 25, when the ion beam passes through the analyzer chamber 231, the guide is a little worn and passes through, when the metal component of the analyzer chamber 231 is introduced It is to cut off. In the configuration of the guides 20 and 20 'such as the present invention, the portions spaced between the contact surfaces 25 between the guides 20 and 20' are removed so that they do not collide with the analyzer chamber 231, and the ion beam Even though passing through, the contact surface 25 is not easily worn.

In addition, the guide 20 is composed of graphite layers such as carbon and carbon which are graphite.

Hereinafter, the operation and effects of the analyzer chamber mounted on the ion implantation apparatus according to the present invention will be described in detail.

When the wafer having completed the preceding process is mounted in the end station 300, the impurity gas is supplied to the ion generating unit 120 of the ion source unit 100.

The ion generating unit 120 ionizes the impurity gas, and the ion extracting unit 140 extracts the ionized impurities into the ion beam moving at a high speed.

At this time, the ion beam extracted from the ion extraction unit 140 is quickly moved to the analyzer chamber 231 of the mass spectrometer 230.

The gate beam 210 is mounted between the mass spectrometer 230 and the ion extraction unit 140 so that the ion beam extracted from the ion extraction unit 140 only when the gate valve 210 is opened as the process proceeds. It is moved to the analyzer chamber 231 of the mass spectrometer 230 at a high speed.

Therefore, when the gate valve 210 is opened, the ion beam extracted from the ion extraction unit 140 flows into the ion inlet 237 formed in the analyzer chamber 231 of the mass spectrometer 230 at a high speed, and then the analyzer chamber. Only ions to be injected into the wafer are selectively separated and selected by an electromagnet mounted in the analyzer chamber 231 while passing through the 231 to form a predetermined magnetic field, and are discharged to the ion outlet 239 of the analyzer chamber 231. .

Thereafter, the ion beam passing through the analyzer chamber 100 of the mass spectrometer 230 is accurately injected into the wafer mounted in the end station 300 via the ion accelerator 250 and the deflection unit 270.

In this case, as the gate valve 210 is extracted by the ion extraction unit 140 and the gate valve 210 is opened, the ion beam rapidly flowing into the ion inlet 237 of the analyzer chamber 231 is introduced into the guide of the analyzer chamber 231. As the spaced portions where the guides face each other are damaged, the metal component of the analyzer chamber 231 is transferred to the wafer together with the ion beam, thereby lowering the yield of the product due to contamination.

However, the grooves 21 and the protrusions 22 are formed to be mounted on the facing portions of the guides 20 coupled to the analyzer chamber 231 according to the present invention, so that the outer wall 23 of the guide 20 is formed. The contact surface 25 may be provided between the inner wall 24 and the inner wall 24, thereby preventing the metal component of the analyzer chamber 231 from being introduced.

As described above, the present invention has the following effects due to the mass spectrometer.

First, a groove is formed on one side facing each other, and guides having protrusions corresponding to the grooves on the other side are continuously coupled to an inner wall of the analyzer chamber, and each adjacent guide is coupled to have a line contact. By eliminating the exposure, when implanting ions into the wafer, the metal components of the chamber inner wall can be transferred along with the ion beam to the wafer to reduce yield degradation due to contamination.

Second, since the grooves and the protrusions of the guides continuously coupled to each other are rounded, the contacting portions have a large area so that the inner wall of the ion beam and the analyzer chamber can be blocked more efficiently.

Claims (3)

In the mass spectrometer used in the ion implantation device for manufacturing a semiconductor device, An analyzer chamber; Electromagnets mounted on the outside of the analyzer chamber; A plurality of guides continuously coupled to the inner wall of the analyzer chamber; And each of the adjacent guides has a plurality of line contacts. The method of claim 1, Each of the guides; Mass spectrometer for manufacturing a semiconductor device, characterized in that the groove is formed on one side facing each other, the projection corresponding to the groove is formed on the other side. The method of claim 2, The guide; One side protrudes to form a rounded protrusion, the other side is a mass spectrometer for manufacturing a semiconductor device, characterized in that the groove is formed corresponding to the protrusion.