KR100575879B1 - Aparratus for curing e-beam using electron cyclotron resonance - Google Patents

Abstract

The present invention discloses an electron beam curing apparatus using an ECR plasma source. According to an aspect of the present invention, there is provided an electron beam curing apparatus using an ECR plasma source, comprising: a plasma generating chamber portion coupled to an upper surface of the vacuum chamber portion by an insulator and a vacuum chamber portion mounted with a wafer therein; A microwave supply unit provided on the plasma generation chamber portion; A non-metallic grid mounted on an opening formed by the plasma generating chamber part and the vacuum chamber part and connected to the low voltage power supply part; A main coil part mounted on an outer circumferential surface of the upper wall of the plasma generation chamber part; A sub coil part mounted on an outer circumferential surface of the plasma generation chamber load side wall; And an auxiliary coil part mounted on the outer circumferential surface of the side wall of the vacuum chamber, thereby creating a different magnetic field in the sub-coil part and the auxiliary coil part of the central chamber and the lower part of the chamber, thereby contributing to improving the uniformity of the plasma distribution and the uniformity of the electron beam. At the same time, the use of Deep-UV PR can prevent line striping and reduce PR selectivity.

Description

Aparratus for curing e-beam using electron cyclotron resonance

1 is a schematic diagram of a curing equipment for explaining the conventional electron beam curing equipment,

2 is a schematic diagram of a curing apparatus for an electron beam curing apparatus using an ECR plasma source according to the present invention;

[Description of Drawing Reference]

31 vacuum chamber portion 31a gas outlet

33 wafer 35 plasma generating chamber

37: insulator 39: conductive grid

41: high voltage power supply unit 43: low voltage power supply unit

45: main coil portion 47: sub-coil portion

49: auxiliary coil part 51: gas discharge pump

B: plasma

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam curing apparatus for manufacturing a semiconductor device, and more particularly, to improve the problems of the existing equipment by modifying an electron source of an E-beam curing apparatus, thereby improving DUB (deep-ultra violet PR). The present invention relates to an electron beam curing apparatus using an ECR plasma source, which can prevent line streaking and reduced PR selectivity due to use.

Dry etching due to excessive PR flow and critical dimension shrinkage during photomask processing using deep-UV PR (photoresist) with ArF (193nm) on devices below 0.117 μm technology In the dry etching process, CD uniformity is drastically lowered due to the occurrence of line striation, and the PR selectivity is also lowered.

Currently, efforts are being made to eliminate this phenomenon by doping electron beams to Deep-UV PR using electron beam curing equipment. The success of this technique requires uniform electron beam intensity and uniform distribution of electrons.

Referring to Figure 1 with respect to the conventional electron beam curing equipment for curing Deep-UV PR in this respect is as follows.

1 is a schematic diagram of a curing apparatus for explaining a conventional electron beam curing equipment.

Conventional electron beam curing equipment, as shown in Figure 1, is equipped with a wafer 13 coated with Deep-UV PR in the vacuum chamber 11, and serves as a cathode on the reaction chamber (11) The generating chamber part 15 is provided, and the vacuum chamber part 11 and the plasma chamber part 15 are insulated by an insulator 17, and an aluminum grid 19 serving as an anode is provided between them. .

Here, the plasma vitalization chamber part 15 is connected to the high voltage power supply unit 21, and the Al grid 19 is connected to the low voltage power supply unit 23.

In addition, a discharge pump 25 for discharging gas is provided in the discharge port 11a formed at the lower end of the vacuum chamber part 11.

In the conventional electron beam curing apparatus having such a configuration, a plasma is generated by applying a DC voltage to the grid 19, which is a cathode and an anode, which is made of metal, and the generated electrons are incident on the wafer 13 to apply the PR. The layer is made to enter the curing.

However, existing electron beam curing equipment uses DC (direct current) plasma, so there is room for improvement of electron beam intensity and electron distribution uniformity. In existing equipment, the cathode and the anode of metal component are directly exposed to the plasma Has become the culprit of pollution.

Therefore, the present invention has been made to solve the above problems of the prior art, by using a modified electron cyclotron resonance (ECR) type plasma source to increase the amount of ions and electrons under a low pressure and to apply a constant voltage to the grid electrode The purpose of the present invention is to provide an electron beam curing apparatus using an ECR plasma source that increases the amount of electron beams and allows only electrons to be selectively incident on a wafer, while ensuring uniform electron beam intensity.

In addition, another object of the present invention is to create a different magnetic field in the sub-coil portion and the auxiliary coil portion in the center and the lower end of the chamber contribute to the uniformity of the plasma distribution and the uniformity of the electron beam and at the same time due to the use of Deep-UV PR The present invention provides an electron beam curing apparatus using an ECR plasma source capable of preventing line fringes and reducing the PR selectivity.

Electron beam curing apparatus using an ECR plasma source according to the present invention for achieving the above object,

In an electron beam curing apparatus using an ECR plasma source, a plasma generating chamber part coupled to an upper surface of the vacuum chamber part by an insulator and connected to an external high voltage power supply part by an insulator, and a vacuum chamber part having a wafer having a photoresist layer formed therein to generate a plasma. Wow; A microwave supply unit provided on the plasma generation chamber portion; A grid mounted on an opening formed by the plasma generating chamber part and the vacuum chamber part and connected to a low voltage power supply part to selectively inject only electrons in the generated plasma into the wafer to cure the photoresist layer; A main coil part mounted on an outer circumferential surface of the upper side wall of the plasma generating chamber part; And a sub coil part and an auxiliary coil part mounted on each of the lower wall of the plasma generating chamber part and the outer circumferential surface of the side wall of the vacuum chamber part to uniformize the generated plasma distribution.

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(Example)

Hereinafter, an electron beam curing apparatus using an ECR plasma source according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic diagram of an apparatus for curing an electron beam curing apparatus using an ECR plasma source according to the present invention.

In the electron beam curing apparatus using the ECR plasma source according to the present invention, as shown in FIG. 2, a wafer 33 having a pores resist layer (not shown) having Deep-UV PR coated therein is formed in the vacuum chamber 31. And a plasma generating chamber 35 serving as a cathode on the reaction chamber 31, the vacuum chamber 31 and the plasma generating chamber 35 are insulated with an insulator 37. Between them, a conductive grid 39 serving as an anode is provided. Here, the conductive grid includes a metallic material such as aluminum or Si which is a non-metallic material.

Here, the plasma generation chamber 35 is connected to the high voltage power supply 41, and the conductive grid 39 is connected to the low voltage power supply 43. In addition, the main coil portion 45 is mounted on the upper outer circumferential surface of the plasma generation chamber portion 35, respectively.

The sub-coil part 47 and the auxiliary coil part 49 are mounted on the lower side of the plasma generation chamber part 35 and the outer circumferential surfaces of the vacuum chamber part 31, respectively, unlike the existing apparatus. In this case, the strength of the magnetic field formed in each of the subcoil portion 47 and the auxiliary coil portion 49 is in the range of 0 to 100G.

On the other hand, the gas discharge port 31a formed at the lower end of the vacuum chamber 31 is provided with a discharge pump 51 for discharging the gas.

The principle of the ECR type plasma generator according to the present invention having such a configuration will be briefly described as follows.

First, a conductive grid 39 made of aluminum or non-metallic Si is fixed between the subcoil portion 47 and the wafer 33 and subjected to a constant voltage to selectively form only the electrons in the plasma B, thereby forming a photoresist layer. It is made to enter the wafer 33.

Here, when the magnetic field is present in the plasma (B), the charge is rotated at a frequency of WC = qB / mc, when a microwave having a frequency w is incident, when w = wc (that is, the electron resonance Energy absorbed by the electrons in the plasma from the microwaves is maximized. 2.45GHz microwave is applied from outside, and electron resonance occurs in the B = 875 Gauss region, and since the mass of ions is much larger than the mass of electrons, most of the microwave energy is absorbed by the electrons. Increasing the radius of the motion and colliding with the neutral particles to ionize the neutral particles to produce a high density plasma.

According to the present invention, the ionization rate is higher than that of conventional RIE (MERIE) plasma and TCP (transformer coupled plasma), and plasma B is generated at a very low pressure (10 mtorr or less). The advantage is that curing of the PR in a cleaner state is possible.

In addition, two different coil parts, that is, the sub coil part 47 and the auxiliary coil part 49, are mounted at the center and the lower end of the chamber, thereby improving the uniformity of the plasma distribution.

As described above, according to the electron beam curing apparatus using the ECR plasma source according to the present invention, by improving the electron beam generating apparatus from the existing DC plasma to the ECR plasma source using a microwave of 2.45 GHz, the following improvement effect is expected. Can be.                     

According to the present invention, since the operating pressure of the ECR plasma is lower than the conventional reactive ion etching (RIE) and TCP (transformer coupled plasma) sources using DC and RF (for example, 10 mtorr or less), the generation efficiency of electrons is increased, The intensity of generated electrons can be improved more uniformly.

In addition, according to the present invention, by generating another magnetic field by winding another coil on the side wall of the vacuum chamber under the subcoil, it is possible to obtain the effect of improving the uniformity of the electron beam distribution and the degree of uniform incidence on the wafer on which the photoresist layer is formed. .

In addition, by controlling the current flowing through the sub coil and the auxiliary coil differently, it is possible to expect the effect of uniformly controlling the uniformity of the plasma and the amount of electron beam incident on the wafer through the grid.

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the invention claimed in the claims. will be.

Claims (4)

In the electron beam curing apparatus using an ECR plasma source, A plasma generation chamber portion coupled to an upper surface of the vacuum chamber portion by an insulator and a vacuum chamber portion on which a wafer having a photoresist layer is formed and connected to an external high voltage power supply portion to generate plasma; A microwave supply unit provided on the plasma generation chamber portion; A grid mounted on an opening formed by the plasma generating chamber part and the vacuum chamber part and connected to a low voltage power supply part to selectively inject only electrons in the generated plasma into the wafer to cure the photoresist layer; A main coil part mounted on an outer circumferential surface of the upper side wall of the plasma generating chamber part; An electron beam using an ECR plasma source, comprising a sub coil part and an auxiliary coil part mounted on each of the lower side wall of the plasma generating chamber part and the outer peripheral surface of the side wall of the vacuum chamber part to uniform the generated plasma distribution. Curing device. The electron beam curing apparatus using an ECR plasma source according to claim 1, wherein the strength of the magnetic field formed in the main coil portion is 875 G. The electron beam curing apparatus using an ECR plasma source according to claim 1, wherein the magnetic field formed in the sub coil part and the magnetic field strength formed in the auxiliary coil part are formed differently. 4. The electron beam curing apparatus using an ECR plasma source according to claim 3, wherein the intensity of the magnetic field formed in each of the subcoil portion and the auxiliary coil portion is in a range of 0 to 100 G.

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