KR20030057934A - Magnetic Enhanced Reactive Ion Etching unit - Google Patents

Abstract

PURPOSE: A magnetic enhanced reactive ion etching apparatus is provided to be capable of improving uniformity when carrying out a plasma etching process by locating a plurality of permanent magnets at an etching chamber according to the gauss intensity of each magnet. CONSTITUTION: A plurality of permanent magnets are installed at an etching chamber. At this time, the permanent magnets are located at each predetermined position after dividing three groups made of the first, second, third group according to the gauss intensity and array position of each permanent magnet. At this time, the gauss intensity at a permanent magnet located position of at least one group, is larger than that of the center portion of the etching chamber. At the time, the gauss intensity of one group out of the other groups is the same as the half value of that of the center portion of the etching chamber, or higher.

Description

Magnetically Enhanced Reactive Ion Etching Unit

The present invention relates to a plasma source of semiconductor etching equipment, and specifically, a permanent magnet for magnetic generation of an etching chamber is divided into a plurality of groups according to a Gaussian size to increase the uniformity during plasma etching. An increased reactive ion etching apparatus is disclosed.

In general, a semiconductor device manufacturing process includes a process of forming a plurality of patterns on a semiconductor substrate, and the pattern is usually formed by performing an etching process.

Recently, as semiconductor devices have been highly integrated, the size of the line width to be realized on a semiconductor substrate is required to be 0.15 μm or less, and thus, a dry etching technique using plasma is widely used in the semiconductor device manufacturing process.

The dry etching technology using the plasma transforms the etching gas into a plasma state by injecting the etching gas into the etching chamber in a high vacuum state through a gas distribution plate (GDP), thereby generating a positive ion or radical of the etching gas in the plasma state. ) And the semiconductor substrate positioned on the fixed pedestal contact each other so that a predetermined region of the semiconductor substrate is etched.

The etching chamber in which the dry etching process using the plasma is performed may include reactive ion etching (RIE), magnetic enhanced reactive ion etching (MERIE), electron cyclotron resonance (ECR), and transformer coupled plasma (TCP) according to a method of forming a plasma. Can be divided into

A focus ring is provided on the pedestal so that the etching gas in the plasma state can be concentrated on the wafer surface located on the pedestal of the etching chamber in which the dry etching process using the plasma is performed, and outside the etching chamber. A uniform plasma may be formed in the etching chamber by installing a plurality of magnetic coils capable of forming a magnetic field.

Hereinafter, a magnetically enhanced reactive ion etching unit of the related art will be described.

1A and 1B are magnetic field strength and B field state diagrams of a typical ME-RIE plasma etching apparatus using coils, and FIGS. 2A and 2B are magnetic field strength and B field state diagrams of a typical ME-RIE plasma etching apparatus using permanent magnets. .

3A and 3B are state diagrams of a permanent magnet arrangement and B field of the prior art.

Figure 1a shows the magnetic strength of a typical ME-RIE plasma etching apparatus by a coil, it can be seen that the uniformity difference is severe due to the concentration of electrons by the magnetic field.

In this case, as shown in FIG. 1B, the uniformity is about 45% based on the 200 mm wafer.

And in the case of using the permanent magnet of Figure 2a is shown that the uniformity is improved than the method using the coil.

In case of ME-RIE method (Di-pole magnet) by permanent magnet, uniformity is more than ± 5% based on 200mm wafer and ± 10% or more based on 300mm wafer.

The prior art Magnetic Enhanced Reactive Ion Etching unit has two permanent magnets (a total of 32) of 180G and 60G, with 180G at the top, 60G at the bottom, and 22.5 degrees each. The centers of the chambers are arranged in 120G.

However, in this method, as shown in Figure 3b, the gauss over the lower portion centered on 120G in the center is relatively weak.

In order to compensate for this, the conventional technique uses a method of rotating a magnet-ring at a speed of 20 RPM, but this is also a limited complement, and this disadvantage will be widened especially when using a wafer of 300 mm or more.

However, such a conventional self-reaction type reactive ion etching apparatus has the following problems.

The ME-RIE method using the permanent magnet of the prior art has much more effect on improving the uniformity than the method using the coil, but there is a difference of more than ± 5%, the maximum value, and the minimum value by more than 10%. Will be bad.

In addition, when there is a region where the internal pressure is imbalanced at the connection portion between the vacuum pump and the etching chamber that controls the pressure state of the etching chamber, the non-uniform plasma is formed by engaging with the non-uniformity of the B field, resulting in a poor etching uniformity. Occurs.

The present invention is to solve the problem of the plasma etching apparatus of the prior art, the technique relates to the plasma source of the semiconductor etching equipment, and specifically, a plurality of permanent magnets for the magnetic generation of the etching chamber according to the Gauss (Gauss) size The present invention is to provide a self-increasing reactive ion etching apparatus which is divided into groups to increase uniformity during plasma etching.

1A and 1B are magnetic field strength and B field state diagrams of a typical ME-RIE plasma etching apparatus using a coil;

2A and 2B are magnetic field strength and B field state diagrams of a typical ME-RIE plasma etching apparatus using a permanent magnet.

3A and 3B show a state of the art permanent magnet placement and B field.

Figure 4a is a configuration of a permanent magnet arrangement of the ME-RIE plasma etching apparatus according to the present invention

4B to 4D are B field state diagrams of the ME-RIE plasma etching apparatus according to the present invention.

Self-increasing reactive ion etching apparatus according to the present invention for achieving the above object by the magnetic field flow of the permanent magnet in the etching chamber, according to the Gaussian size and arrangement position of the permanent magnet 3 group, 2 group, 3 group The Gaussian size at the position where the permanent magnets of at least one group are located is larger than the Gaussian size of the center, and one group of the remaining groups is smaller than half the center Gaussian size. It characterized in that the control to be greater than or equal to.

Hereinafter, the self-increasing reactive ion etching apparatus according to the present invention will be described in detail.

Figure 4a is a configuration diagram of a permanent magnet of the ME-RIE plasma etching apparatus according to the present invention, Figures 4b to 4d is a B field state diagram of the ME-RIE plasma etching apparatus according to the present invention.

The present invention is to uniformize the flow of the B-field (magnetic field by the permanent magnet) affecting the uniformity in the chamber (chamber) of the etching equipment to be used in future 300mm wafer processing technology.

The present invention improves uniformity by arranging three or more kinds of permanent magnets having different magnetic fields in consideration of the flow direction of a B field having a Gaussian size.

In other words, in order to make the flow of the B field more stable in the dual pole, the poles are multiplied to improve the B field inside the chamber.

Too many poles, however, cause the mutual interference (offset and rise) effects of the B fields, which may result in local uniformity control.

In the case of Figure 4a is configured to have three poles in consideration of this.

Gauss in the center area is set based on existing equipment, and the Gaussian setting on the outside can be changed according to design intention.

Magnetic Enhanced Reactive Ion Etching unit according to the present invention has a 120G in the center region, as shown in Figure 4a, and the 180 gauss permanent magnet and 90 gauss permanent magnet around the etching chamber 36 It is composed of 48 or 48 items.

In this case, as shown in FIG. 4B, the gauss applied to the lower side of the center is reinforced to increase the uniformity.

As described above, when the permanent magnets having different Gaussian sizes are classified into three groups of 1 group, 2 groups, and 3 groups according to the arrangement position, as shown in FIGS. 4B, 4C, and 4D, You can control the B field inside the chamber by arranging the Gaussian size as 1 group> 2 group = 3 group, and control the B field inside the chamber by arranging the Gaussian size of permanent magnet as 1 group = 2 group> 3 group. It is possible to control the B field inside the chamber by arranging the Gaussian size of the permanent magnets as 1 group> 2 groups> 3 groups.

Here, when the size of the Gaussian is arranged into 1 group> 2 group> 3 group, the B field may be controlled by slightly increasing the degree of asymmetry.

Such a self-increasing reactive ion etching apparatus according to the present invention has the following effects.

The present invention can improve the degree of concentration of the B field by varying the arrangement of the permanent magnets.

This is because the concentration of the B field is different in the uniformity improvement effect during plasma etching, thereby suppressing the uniformity difference occurring at the center and edge or edge and edge when rotating it.

This method can be used not only for plasma etch equipment, but also for LCD equipment or thin film equipment using plasma.

Claims (4)

Magnetic field flow by the permanent magnet in the etching chamber, According to the Gaussian size and arrangement position of the permanent magnet is configured to be divided into three groups, 1 group, 2 groups, 3 groups, Gaussian size at the position where the permanent magnets of at least one group is located is larger than the Gaussian size of the center, and one of the remaining groups is controlled to be greater than or equal to 1/2 of the center Gaussian size Self-increasing reactive ion etching device. The method of claim 1, A self-increasing reactive ion etching apparatus having 120 G in the center region and comprising 36 or 48 arrays of 180 gauss permanent magnets and 90 gauss permanent magnets around the etching chamber. The method of claim 1, Gaussian size of permanent magnets in group 1> 2 groups = 3 groups, Gaussian size of permanent magnets in group 1 = 2 groups> 3 groups, or Gaussian size of permanent magnets in group 1> 2 groups> 3 groups Self-increasing reactive ion etching apparatus, characterized in that arranged in the. The method of claim 3, wherein Self-increasing reactive ion etching apparatus, characterized in that the arrangement of the Gaussian size of the permanent magnet group 1> group 2> 3 so that the flow of the magnetic field of the B field is asymmetric.