JPS5853833A - Plasma etching device - Google Patents

Abstract

PURPOSE:To reduce the production of dust to the extreme degree, by heating the surface of an anode to 50 deg.C or more by using a heater, when the parallel-flat type electrode loaded with the anode and the material to be etched and constituted of the cathode whereon a high frequency power is inpressed is contained into a pressure reduction vessel, and halogen compound gas is introduced resulting in the etching of the material to be etched. CONSTITUTION:The parallel-flat type electrode constituted of a pair of electrode opposed each other, i.e. the cathode 17 and the anode 19 is arranged in the pressure reduction vessel 26, the material to be etched 18 is loaded on the electrode 17, a carbon plate 28 is adhered on the lower surface of the electrode 19. Next, the mixed gas with CF4 and H2 is introduced into the pressure reduction vessel 26, and the high frequency power from the power source 15 is impressed on the cathode 17 via a matching circuit 14 resulting in the generation of plasma between the cathode 17 and the anode 19, and accordingly the material to be etched 18 is etched. In this constitution, the heater 22 with a built-in hot wire 21 is contacted on the back surface of the anode 19, and the anode 19 kept heated to 50 deg.C or more by passing the current from a current source 20. Thus, the dispersion of polymers from the carbon plate 28 is not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plasma etching apparatus that generates less dust.

In recent years, the etching method for manufacturing integrated circuits has been
Conventionally, the Pukusuma Etender method using O-ized JP crystals and the Pukusma Etender method using a reactive gas such as CF4 has been used.

According to the conventional etching method, the etching method can be simplified compared to the conventional wet ettender.

It is excellent in terms of improvement in pattern dimensional accuracy and ease of use.

Of these, CF4, C, j', or CC
l2.

vh9 reactive ion etching using Cjs Ill reactive gas (R@gt1v@Ion ltchinp
The main method is called RI m).For example, to form a contact hole, H is mixed into CF, and 9 gases are mixed into 9 gases, 9 gases are mixed with 9 gases, 9 gases are mixed with 9 gases, and 1 hole is used as a wiring material. Etching method of ▲) Gasputsuma t'' raw jI! ions (positive ions) and neutral active species (atoms) in the plasma of ζ. At present, there is a practical R#C using 9 etch/da using the chemical/tkHL reaction between the molecule and the object to be etched.

A typical aspect of this aI phylum is considered in the next OIl.

In other words, if the gray discharge (by applying high frequency power such as an electric current f& (hereinafter referred to as cathode) K, 115, etc.) placed parallel to each other φ is relaxed, electrons and After applying the ion frequency power, after applying the high frequency power, a negative potential is applied to the cathode surface (hereinafter, this potential is constant from II pigeon potential and is referred to as Vd). occurs,
It becomes a steady state.

On the other hand, the electrode facing the cathode (hereinafter referred to as anode)
The potential of the surface is at most the plasma potential (20~30@V)! jA
degree. The first II can be arranged far parallel to the cathode (
1) It is clear from the fact that the number is greater than 0 that the positive ions in the plasma are generated by the high frequency power a1, and the positive ions in the plasma are 5v41eK. For example, a hot gas of cr, +u is applied as the reactive gas, and oxidized plasma is applied as the object to be etched. Nine undercuts seen in etching etc. do not occur at all,
Nine etching profiles can be obtained by using a straight etching bell, and microfabrication can be achieved. However, conventional 0RIi! In the i@ arrangement, the object to be etched (3) is placed directly under the counter electrode, i.e., the positive@(2), so that the influence of dust that accumulates in the gas phase is essentially eliminated. For example, when a pulled S film is etched with a gas plasma of a heated gas of CP and 10H, a large amount of unsaturated monomers such as CF are generated in the gas phase. , this 7-mer undergoes a polymerization reaction on the anode, which has a low potential (as seen from the plasma), and is deposited as a polymeric film, that is, a theanium-based O polymer group (CF, )aoIl. This polymerized metal increases in thickness as the discharge time increases, and eventually cracks and peels due to internal strain, which accumulates on the object to be etched (3) and causes dust. becomes. This dust not only causes a significant decrease in yield (yield), but also requires frequent cleaning of equipment such as the production pulley 7, which is a serious problem in the maintenance pipe moim.

The present invention has been made in view of the above points, and is an object of the present invention, which includes nine pairs of parallel planes arranged opposite to each other, and an electrode surface facing the electrode on which the object to be etched is placed in the Makio Den IIO. By providing a heater that heats the device as described above, it is possible to prevent the pre-polymerization film from being deposited on the electrode, thereby providing a material etching device that generates extremely little dust.

Hereinafter, embodiments of the present invention will be described in detail in 11A with reference to the drawings.
K@@Sui.

The 2nd m11 connects the 1154th Dll pole (2) to the pipe (
7) With a device that heats with a heater, CF, +H, and gas are introduced and discharged.
! This figure shows the relationship between the surface temperature and the degree of deposition of the polymer film on the anode surface. Gas pressure is 0.04 Torr, flow rate ratio φ/Qoy4x 1.0 (Qoy,! 1osoo
u QH,: 2G800M), RF power 30O
It is W. The same figure] As is clear, as the temperature of the 1!1 surface increases, the polymer film grows under its own weight, and at SO℃ the deposition is all m
k le, CFa+H* (D base b D K CF4.
Halogen compound gas containing C and r such as C*fs, C5Fa, or by adding H to these gases
F, CHF, -4-H.

Even if a gas containing the same OC, r, and H is used, it will grow with the heating of the anode (by heating the anode to 50° C. or higher), a permanent improvement can be observed. The above results are actually the same even when etching 8iO1.

As described above, by heating the positive surface, deposition of p-polymerized metals is suppressed, and the temperature is preferably sO°C or higher. Yes, it has been known to discharge CF4 gas in advance and coat the anode and container wall with a polymer metal in order to protect the device from metal contamination such as stainless steel from the vacuum container. However, by heating the anode, the tinging is removed. Therefore, to prevent metal contamination, carbon plates are attached to the anode and the inner wall of the container), hydrocarbon-based, and fluorine-based.

It is sufficient to attach a diluted hydrocarbon-based or silicon-based film.

Figure 3 shows an example of the nine depths based on this idea. That is, a pair of electrodes are provided facing each other, and among the nine parallel flat plate electrodes, an electric field of 1! For example, a carbon plate is placed in close contact with the surface of the electrode 8IlR facing the electrode 8, and the ground electrodes other than the wrinkled anode are covered with, for example, a polyester film.
, On the upper side of the vacuum container, the one containing the heat rays is placed in close contact with the other. The temperature of the anode surface is controlled by the current value of the current IK. As explained above, due to the large device configuration, there are no exposed metal parts in the p1 reaction vessel),
Therefore, it can be confirmed that when the metal contaminants are completely cast, there is almost no deposition of polymer film on the carbon plate (2). The result shown in the figure is that even if the carbon plate (2) is provided in this way, there is no change at all. In that case, the anode surface temperature indicates the carbon plate (2) surface temperature.

In the fourth m, in this example, it is possible to examine the progress of the non-defective product rate after etching with respect to the discharge time.In the conventional example, when the discharge time exceeds 100 hours, most non-defective products are obtained and the state is tk%/%. It can be seen that there is almost no decline in the non-defective product rate (solid line) for 59 products (dashed line), 3rd g.
In the embodiment shown in Figure 2, a case was shown in which only the counter electrode ri- was heated, but all other ground electrodes such as the container (to) were heated.
It has been confirmed that a similar effect can be obtained when heated at the same time.

Ceramics, the present invention is 8101o et al., Sl, N, Yamuj, po
It can also be applied to etching ly-8i etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional etching apparatus, FIG. 2 is a characteristic diagram showing the relationship between anode surface temperature and polymerization rate, fs3 is a sectional view of an etching apparatus for explaining the present invention in detail, and FIG. The figure is a characteristic diagram for explaining the effects of the embodiment of the present invention. In the figure, (l) αη... cathode, (2)
aL... Anode, (3) OL... Etched 'II1.
<4) @...Reduced pressure container, (5) (1119-#
water inlet, (6) (7) (to)... water cooling pipe, (
8)(9)@■...Teflon, (111(14)・
...marching circuit, al)as...high frequency power supply, α
I [...Exhaust system. (I field...Polymer film, @...Carbon plate, (2)...Polyester film. ■...Heat sink, Ql)...Heat wire, (E)...
・Current source. Agent Benshio Kensuke Norichika and 1 other person Figure 1 Figure 2 Rebellion Fifth Degree (τ) Figure 8 □ Figure 4 1 What? 619 3. @ ω Key number 1 and “Scream I!”: 1 (hy)

Claims (3)

[Claims] (1) A reduced pressure container, a parallel plate type electrode consisting of nine anodes which are arranged opposite to each other in this reduced pressure container, and a cathode on which high frequency power is applied and the object to be etched is placed, and a halogen in this reduced pressure container. means for introducing a compound gas;
1. A plasma etching apparatus comprising: a heater for heating an i-configuration electrode surface to a temperature of 50° C. or higher. (2) The plasma etching apparatus according to item 1 of the patent scope, wherein the anode surface is made of a carbon plate or a hydrocarbon-based, fluorine-based, carbon-hydrogen-nitride-based or silicon-based film. (3) The plasma etching apparatus according to item 1 of the patent application, characterized in that a gas containing C and F is introduced.