JPS6045024A - Dry etching device - Google Patents

Abstract

PURPOSE:To enable to etch in a high speed the various kinds of semiconductor manufacturing materials, and moreover, to enable to check previously generation of ion damage at a dry etching device by a method wherein a magnetic field generated according to magnets is applied to the direction to meet at right angles with an electric field at usually reactive ion etching. CONSTITUTION:Gutter type electrodes 4a, 4b are arranged oppositely along the outer peripheral surface of a bell jar 1 on the outside of the bell jar 1. A permanent magnet 7a is arranged over a sample desk 2, and a permanent magnet 7b is fitted to the under surface of the sample desk 2. Reactive gas is introduced from a gas introducing port into the vacuum vessel 1, and gas in the vacuum vessel 1 is exhausted from a gas exhaust port. When a dry etching device is formed in such a construction, electrons (e) perform drift motion in space on a sample 3 according to actions of an electric field E generated by the electrodes 4a, 4b and a magnetic field B generated by the magnets 7a, 7b and to meet at right angles with the electric field, and motion length thereof is elongated substantially. Accordingly, frequency of collisions of electrons and reactive gas is increased sharply, and as a result, efficiency of ionization is enhanced sharply.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a dry etching apparatus used for manufacturing semiconductor devices, and more specifically to a dry etching apparatus that utilizes a magnetic field generated by a permanent magnet.

[Background of the invention and its problems] In recent years, semiconductor integrated circuits have been becoming increasingly finer, and recently the minimum dimensions have become smaller than 1.
A 2 [μm] ultra-LSI has also been produced as a prototype. For this microfabrication, CF4 was placed in a vacuum container with parallel plate electrodes.
By introducing a reactive gas such as or CC+4 and applying high frequency power to the electrode on which the sample is placed, glow lightning is generated, and the negative DC self-bias (cathode drop voltage) generated in this electrode causes Reactive ion etching (twisting) involves accelerating positive ions and irradiating them perpendicularly to the sample.
RIE: ReacHve l onEtchin
q) or attract attention -C.

However, in this RIE, for example, when etching 5 iOz using CF4 1H2 gas, the etching speed is only 300 to 400 [ml + 1], and 1
It takes several tens of minutes to cover [μm] of SiO2 by etching. Furthermore, the etching speed was slow for Δ1 and poly 3i, and the mass productivity was poor. It is known that in order to increase the etching speed, it is somewhat effective to make the input hole J larger, but in this case, the shadow (yoyo descending type D)
There was a risk that E would be reduced, ion damage would occur, the etching iU selectivity would be determined by the sputtering ratio, and the resist would become hot and deform.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a dry etching apparatus capable of high-speed etching of various types of semiconductor manufacturing (i-format) and also capable of preventing ion beam formation.

[Summary of the invention]

The gist of the present invention is to apply a magnetic field by a magnet in a direction perpendicular to the direction of the electric field in normal RIE, thereby increasing the ionization efficiency within the etching chamber.

That is, the present invention provides means for introducing a reactive gas into a vacuum container in which a sample to be egged is placed, and a means for introducing the container outside the container in dry etching II for etching materials for manufacturing semiconductor devices. A pair of WHIMs are disposed facing each other and excite high-frequency plasma discharge in the space where the sample is placed, and a pair of WHIMs are disposed facing each other with the sample between them and are placed in the space where the sample is placed. A pair of permanent magnets are provided that apply one field in a direction perpendicular to the direction of the electric field generated by 1ttIi.

Further, in the dry etching apparatus having the above configuration, the present invention provides an electrode (second electrode) that applies an electric field in the same direction as the direction of fI HA application by the magnet, separately from the electric glue (first electrode). ().

〔Effect of the invention〕

According to the present invention, electrons can be caused to undergo Leekroid motion by the action of the electric field generated by the first electrode and the magnetic field generated by the permanent magnet, and due to the substantial extension of the length of motion of the electrons, they are able to interact with reactive gas molecules. Sudden fJR degree increases significantly. Therefore, the ion efficiency is greatly improved, and the etching rate can therefore be increased. Further, since there is no need to increase the cathode fall voltage, generation of ions 110 can be prevented. Therefore, it is extremely useful in the field of half manufacturing technology.7 [Embodiments of the Invention] FIGS. <(Figure 1 is a vertical cross-sectional view, and Figure 20 is a cross-sectional view, showing the M formation.

Is 1 in the diagram Verge 1 of quartz-1? r (true 2 containers). A water-cooled sample stage 2 is placed inside this verge t+1, and on the sample stage 2 there is a
There are many things that will be posted. On the outside of the bell jar 1, there are 4-shaped Ti poles 4a, 4 on the outer peripheral surface of the bell jar 1.
b is facing ii! It is placed. Then C1 these 1fl
High frequency power is applied from a -C high frequency power source 6 through a matching circuit 5 between Ii4a and Ii4b.

The configuration up to this point is similar to the conventional device, and in this embodiment, permanent magnets 7a and 7b are newly disposed inside the bell jar 1 to face each other. 1, a permanent magnet 7a is disposed above the sample stage 2, and a permanent magnet 7b is disposed on the lower surface of the sample stage 1.
is attached.

In addition, the surfaces of the magnets 7a and 7b are coated with an insulating layer 8a made of quartz, fluororesin, etc. to avoid metal contamination from the magnets 7a and 7b.
8b is applied. Note that 9 in the figure indicates a water-cooled pipe. Although not shown in the figure, a reactive gas is introduced into the vacuum container 1 from a gas inlet, and the gas in the vacuum container 1 is exhausted from a gas exhaust port.

If this is the case, the electric field E due to the N poles 4a and 4b
Due to the action of the magnetic field B generated by the magnets 7a and 7b, the electrons e drift in the space above the specimen 3 (cycloid motion), and their length of motion is substantially extended. -ru. Therefore, the brightness of the collision between the electrons and the reactive gas is greatly increased, and as a result, the ionization efficiency is greatly improved. The high plasma region 10 generated at this time is magnetized by the magnet 4a.
.

Trapped between 4b. Therefore, the etching speed of the sample 3 to be etched is increased. Moreover, since there is no need to increase the cathode fall voltage, there is no problem of ion damage. Conversely, the same etching speed as before is 1
To achieve this, the ion acceleration voltage can be lowered. In fact, the radiation damage was reduced by 1 compared to the 11th generation device.
, /' It was confirmed that C can be reduced to IO.

Moreover, according to the actual situation of the present invention, reaction 1! When 5i02 was 1-twisted using CF4 as the lumber, an etching speed of about 160 [μIn/In I I+ ] was achieved, and the etching uniformity and test sample 13 side magnet 8
By making the diameter of b sufficiently large, ±1-2 [%] can be obtained, which is extremely good (direction is 17%).

FIG. 3 is a cross-sectional view schematically showing the combination of the second embodiment. Note that the same parts as in the first figure are given the same reference numerals, and detailed explanation thereof will be omitted. This embodiment differs from the first embodiment described above in that an electrode (electron reflection plate) for electron repulsion is provided in addition to the electrodes 4a and 4b. That is, on the outer periphery of the bell jar 1, electric currents t14a, 4 are provided.
The frosted cloth 61 temporary 21a and 21b are arranged facing each other in a relationship perpendicular to b. A negative voltage is applied to these electron reflection plates from DC power supplies 22a and 22b.

Of course, even with such a combination, there is an interpolation effect as in the previous embodiment. Also, the reflection tN21a,2
By providing 1b, the ionization efficiency can be further improved, and the etching rate can be increased more than in the previous embodiment. That is, the electron reflection plates 21a, 21
If b is not present, the electrons in the orbit of Drift I will disappear from the plasma due to a collision with the wall of the bell jar 1, but due to the presence of the reflectors 21a and 21b, the length of the orbit will be significantly extended as shown in the figure. This results in a significant addition of 1 to 100% of the ionization.

FIG. 4 is a cross-sectional view of one set showing the lfW Fi'i In structure of the third embodiment. Note that the same parts as in FIG. In addition, the direction perpendicular to the direction of the electric field due to the electric currents 4a and 4b < J to NIE7a and 7b, if
Electric field is applied in the direction (field application direction) = (second north pole)
This is because we have established 1. An electric wire (U31a) is placed below the magnet 7a, and an electric wire (U31a) is placed on the upper surface of the group 57E.
! ! aib is arranged, and these electrodes 31a, 31b are placed on both sides of the sample F13. The two are facing each other. Here, the electrode 3 l b is the same as the above sample! 31 machines will be used for the 20s, and the trial 1°+13 will be placed on the 1- of -Te. The coil 3 is connected between the electric wires 4131a and 31b.
A DC voltage is applied by a DC power supply 33 through C. Also, although not shown in the figure, it is cooled by a water-cooled pipe or the like.

On the other hand, on the inner wall surface of the bell jar 1, a pair of auxiliary supports are provided on the inner wall surface of the bell jar 1 so as to face the electrodes 4a and 4b by 4 degrees, respectively. (sfi34a.

3/Ib is attached. The auxiliary electrode 34b facing the electrode 4b for applying high frequency power is the electrode 3 on which the sample is placed.
1b.

With such a configuration, the electric field caused by the electrodes /Ia and /Ib and the river stone 7a perpendicular to this are similar to the first embodiment.
, 7b can increase the efficiency of ion 1 due to the effect of the magnetic field, and the effect similar to that of the first embodiment can be obtained. 19. In other words, auxiliary 1f! 1i
A high frequency voltage is induced on the bell jar 34b via the wall capacitance of the bell jar 1 (<Cw), and by appropriately selecting the voltage of the variable DC power supply 33, the voltage of the electrode 311) and the sample II
A DC voltage obtained by multiplying the AC voltage by 4#J is applied to the surface 3.

Here, the impedance of the coil 32 needs to be sufficiently larger than the capacitance impedance. Therefore, when the charge with the opposite sign to the charged charge is at a specific phase angle of the AC FA voltage, the sample 3
As a result, the etching profile that is considered to be caused by the charging phenomenon does not occur. The etching without the Anku cut is achieved.

It should be noted that the etching characteristics shown here are the same as when the electrode 31b is in the plasma (or in the afterglow area away from the plasma),
Opposing iNv to 1b! 31a (J, approximately the same result can be obtained even if it is in a floating state or in a grounded state. Also,
As a method of synergizing the DC voltage with the AC voltage, as shown in FIG. 5, an AC power generation source 37 may be newly provided, and basically the DC voltage may be synergized by the capacitor 36 and the coil 32. Furthermore, test 1'i+3 and electric? M
311) A dielectric material, such as Fumiki Un, is laid between the
i, the above-mentioned effects are the same.

Note that the present invention is not limited to the eight embodiments described above. For example, the distribution of the permanent V4i stones is not necessarily limited to inside the bell jar, but may be placed outside the bell jar. However, in the placement space of the sample, the first electric power! It is necessary to apply the moon in a direction perpendicular to the electric field caused by Isamu. In addition, conditions such as the strength of the electric field and magnetic field applied to the space where the sample is placed are determined according to the specifications.
It may be determined as appropriate. Furthermore, the size, shape, etc. of the vacuum container can be changed as appropriate. Furthermore, it goes without saying that the present invention is applicable not only to etching of S+02 but also to etching of various materials for manufacturing semiconductor devices. Other modifications may be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

1 and 2 show the general structure of a dry etching apparatus according to a first embodiment of the present invention.
The figure is a longitudinal sectional view, FIG. 2 is a conventional sectional view, FIG. 3 is a 1FtlfIi side view showing the schematic development of the second embodiment, and FIGS. 4 and 5 are schematic diagrams of the third embodiment. FIG. 1...Verge V, 2...Sample stage, 3...Target 1
Tsuching sample, 4a, 4b-f4'lI)'Fit@
, 5-... Matching circuit, 6... High frequency 71\ source, 7a. 7b... Nagakawaishi, 1o... High density front plus 7.2
18.21b ---electron layer flJ (Ii, 22a,
221) - DC power supply, 31a, 311)...second electric power 1·π. Applicant's agent Patent attorney Yohiko Suzue Figure 1 Figure 2 V'L3 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] (1) A means for introducing a reactive gas into a vacuum container in which a sample to be etched is placed; It comprises a pair of electrodes that excite plasma discharge, and a pair of permanent magnets that are placed facing each other with the sample in between and that apply a magnetic field to the space where the sample is placed in a direction perpendicular to the direction of the electric field produced by the electrodes. A dry etching device featuring: (2) The scope of the claim characterized in that the sample is placed on a test stand disposed within the vacuum container, and the test stand is wetted. Tri-etching device according to item 11n. (3) The tri-etching apparatus according to claim 1, wherein the vacuum vessel is provided with an electron beam 61 along with the electrode on the outside thereof. (4) A hand R for introducing a reactive gas into the vacuum container in which the sample to be etched is placed, and a hand R that is placed opposite to the outside of the container with the container in between, and a high-frequency plasma discharge is applied to the space (6) where the sample is placed. A pair of excited σ) first electrodes and the PIIt are arranged opposite to each other with the sample in between, and the above-mentioned ?
! A pair of second electrodes that apply an electric field in a direction perpendicular to the direction of the electric field caused by the poles, and a pair of second electrodes that are placed facing each other and spaced apart from each other with the sample in between, are applied in the space of the sample mounting area in a direction parallel to the direction of N rise by the second electrodes. [A tri-etching device characterized by comprising a pair of permanent magnets that apply a magnetic field. (5) the second electrode is disposed within the vacuum container;
The dry etching apparatus according to claim 4, characterized in that the sample is disposed on one side of the dry etching apparatus. The tri-etching device according to claim 4, characterized in that: (7) the second Wi pole is applied with a DC voltage superimposed on an AC voltage; The dry etching apparatus according to claim 4, wherein the bias is adjusted according to conditions. (8) The means for adjusting the bias is performed by changing a DC voltage. 8. A dry etching apparatus according to claim 7, wherein the dry etching apparatus is a dry etching apparatus.