JPH02292822A - Semiconductor manufacturing device - Google Patents

Abstract

PURPOSE:To eliminate any oxide produced by and scattered from a wafer holder thereby enabling the dust in a chamber to be minimized by a method wherein a holding frame part made of a high melting point metal or aluminum for fastening a wafer is fixed to a wafer holding base part having an electrode function. CONSTITUTION:The title semiconductor manufacturing device is provided with a chamber 17, an anode electrode 20 of one polarity provided in the chamber 17, a wafer holding substrate part 12 for mounting a wafer 16 having an electrode function of another polarity pairing with the said electrode 20, a holding frame part 13 (titanium) made of a high melting point metal or aluminum for fastening the wafer 16. For example, the said high melting point metal is titanium or zirconium. Through these procedures, the wafer holding substrate part 12 can be prevented from forming a source of an oxide. Accordingly, for example, the contact resistance between the lower metallic film and the upper layer metallic film formed on the wafer 16 can be minimized. Furthermore, the dust of the oxide, etc., in the chamber 17 can be minimized thereby enabling the yield of the semiconductor device to be increased.

Description

[Detailed Description of the Invention] [Summary] Regarding semiconductor manufacturing equipment, more specifically, regarding a wafer holder for placing a wafer in a chamber, it is possible to eliminate oxides generated and scattered from the wafer holder, and to eliminate oxides in the chamber. The purpose of the present invention is to provide a semiconductor manufacturing apparatus that can reduce dust, and includes a chamber, an electrode of one polarity provided in the chamber, and an electrode of another polarity paired with the electrode of one polarity. A structure comprising: a holding base portion having an electrode function on which a wafer is placed; and a holding frame portion made of a high melting point metal or aluminum and attached to the wafer holding base portion for retaining the wafer. do.

[Industrial Field of Application] The present invention relates to semiconductor manufacturing equipment, and more specifically, to a wafer holder for mounting a wafer in a chamber.

[Conventional technology]

FIG. 5 is a sectional view of a conventional sputter etching apparatus. In the same figure, 6 is a chamber where the etching process is performed, 7 is an exhaust port in the chamber 6, 8 is a gas inlet for introducing argon gas, 9 is a stainless steel anode electrode, and 10 is a wafer 5 to be etched. A wafer holder for NQW processing, and functions as a cathode electrode. 11 is an AC power supply for applying voltage between the anode electrode 8 and the cathode electrode, and 6a is an AC voltage shield ring with quartz glass provided on the stainless steel surface, which is kept at the same potential as the wafer holder 10. It's dripping. Also,
9a is lfil&ring between the anode electrode 8 and the cathode electrode.

FIG. 6 is a diagram for explaining the wafer holder 10 in more detail; FIG. 6(a) is a front view, and FIG. It is a diagram. In the figure, 1 is a holding base made of stainless steel, and 2 is a holding frame made of quartz for holding a wafer. It also has the function of preventing defeat. 2a is a wafer support bin for supporting a wafer; 3 is a wafer mounting surface; 4 is a support rod for supporting the holding base portion 1; and 5 is a placed wafer.

Next, using a sputter etching device, the lower layer A1 pattern 8F shown in FIG. The case of removing the alumina film 27 naturally formed on the surface of the alumina film 25 will be explained with reference to FIGS. 5 and 6.

First, the wafer 5 is placed on the wafer mounting surface 3 of the wafer holder 10 provided in the chamber 6, and the wafer 5 is supported by two wafer support pins 2a and set in the chamber 6, and then the air is evacuated. Argon gas is introduced into the chamber 6 through the gas introduction port 8 while evacuating the inside of the chamber 6 through the port 7 .

Next, the anode ? A voltage is applied between the IT pole 9 and the wafer holder 10 (cathode electrode) to ionize the argon gas. As a result, the ionized argon particles move toward the wafer 5 due to the electric field and collide with each other, etching the alumina film 27.

After the etching is completed, in order to prevent the surface of the lower A+ wiring 25 from being oxidized again, this wafer 5 is sent to another substrate without being exposed to the atmosphere, and a layer (not shown) is placed on the lower 5 AI wiring 25. A 11AI film is formed on the top.

? [Problems to be Solved by the Invention] Incidentally, during the etching of the alumina film 27, the quartz of the holding frame portion 2 around the wafer is also bombarded with argon ions.

As a result, the quartz is etched and destroyed, and part of it adheres to the wafer and the other part adheres to parts such as the anode electrode 9 in the chamber 6.

The quartz piece (SiO2) attached to the wafer 5 oxidizes the surface of the lower J5AI gland 25 with oxygen contained in the quartz piece, forming an alumina film again. Therefore, the contact resistance between the upper layer A1 wiring and the lower layer Al wiring 25, which will be formed later on, increases.

Particularly in the case of fine patterns, since the contact portions are small, there is a problem that the contact resistance becomes extremely large or that electrical connection cannot be obtained.

On the other hand, the quartz pieces that adhere to parts such as the stainless steel anode electrode 9 in the chamber 6 are piled up one after another.
A thick film of silicon oxide is formed.

However, since the adhesion of silicon oxide to stainless steel is not very good, the adhered oxide often peels off, resulting in the generation of dust.

The present invention has been made in view of these conventional problems.
It is an object of the present invention to provide a semiconductor manufacturing apparatus that can eliminate flying oxides from a wafer holder and reduce dust in a chamber.

(Means for Solving the Problems) The above-mentioned problems include a chamber, an electrode of one polarity provided in the chamber, and an electrode of another polarity paired with the electrode of one polarity. Solved by a semiconductor manufacturing apparatus characterized by having a holding base part for holding a wafer in R7J1, and a holding frame part made of a high melting point metal or aluminum and attached to the wafer holding base part for locking the wafer. be done.

[Function] When performing a dry etching process using the semiconductor manufacturing apparatus of the present invention, for example, when removing metal oxide naturally generated on the surface of lower metal wiring on a wafer with an etching gas, the etching gas is used to hold the wafer. It also collides with the frame, and the cough wafer holding frame is also etched at the same time.

However, since the wafer holding frame is made of high-melting point metal or aluminum, even if etched pieces of the high-melting point metal film adhere to the lower metal wiring, there will be a gap between the wafer holding frame and the upper metal film formed in the next process. The contact resistance will not increase and the electrical connection will not be compromised.

In particular, if aluminum or titanium or zirconium, which easily combines with oxygen, is used as a metal with a high melting point, it is possible to adsorb oxygen in the chamber and more completely prevent oxidation of the surface of the lower metal wiring, so that it is possible to prevent oxidation of the lower metal wiring surface. The contact resistance between the two can be further reduced.

In addition, stainless steel and aluminum are used as materials for parts such as electrodes in the chamber for -C, but the high melting point metals attached to these materials have a higher VV with stainless steel and aluminum than with conventional silicon oxide. ! Since it has good adhesion, it causes less dust and enables clean etching.

〔Example〕

Next, embodiments of the tree invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a Svanta etching apparatus for anode cambling according to an embodiment of the present invention.

In the figure, 17 is a chamber, 18 is an exhaust port in the chamber 17, 19 is a gas inlet for introducing etching gas such as argon, 2o is an anode electrode to which a voltage is applied to ionize the etching gas, 21 is a wafer holder that has the function of holding the wafer 16 to be etched and also functions as a cathode electrode; 22 is an AC Tl' for applying voltage between the anode electrode 20 and the wafer holder 21; Jl, 17a is an AC voltage shield ring having a stainless steel surface covered with quartz glass, and is maintained at the same potential as the wafer holder 21. Further, 20a is an insulating ring between the anode electrode and the cathode electrode.

FIG. 2 is a diagram for explaining the wafer holder 21 in more detail, ID (a) is a front view, and ID (b) is an arrow BB shown by the dashed line in FIG. FIG.

In the figure, l2 is a holding base made of stainless steel;
13 is a holding frame made of titanium, which is a high melting point metal material, provided on the holding base part 12; 13a is a wafer support bin made of titanium; 14 is a wafer placement surface on which a wafer 16 is placed;
15 is a support rod for supporting the holding base portion 12, and l6 is ffi! This is a wafer that has been subjected to

Next, using the above spatter etching equipment, ? Ji
The case of removing an alumina film naturally formed on an Al wiring will be described with reference to FIGS. 1, 2, and 3.

FIG. 3 is a cross-sectional view of a portion of the wafer before such processing is performed. In the same part, 23 is a Si substrate, 24 is a SiO2 film on a Si-based temporary 23, 25 is a lower layer AI wiring on a Sing film 24, and 26 is a 1.5 μm Xl for contact.
, 27 is an alumina film naturally formed on the surface of the lower layer A1 wiring 25 at the bottom of the through hole.

First, the wafer 16 is placed on the wafer placement surface 14 of the wafer holder 21 provided in the chamber 17 and supported by the two wafer support bins 13a, and then the support rod 15 is raised and set in a predetermined position. do.

Next, the inside of the chamber 17 is evacuated from the exhaust port 18 . Next, argon gas is introduced into the chamber 17 from the gas inlet 19 and the pressure is adjusted to 5 mmTorr.

Next, the AC power supply 22 is turned on to connect the anode electrode 20 and the wafer holder 21, which is the cathode electrode, at a frequency of 13.
An alternating current voltage of 56 MHz (power: 300 W) is applied.

At this time, the argon gas is ionized, and the ionized argon particles head toward the cathode side and collide with the wafer 16 and the wafer holding frame 13. As a result, the anode electrode 20
A current flows between the wafer holder 21 and the wafer holder 21 (cathode electrode). As a result, the alumina film 27 on the surface of the lower layer A1 wiring 25 is etched.

At the same time, the titanium of the holding frame portion 13 is also etched and lit. A part of this adheres to the anode electrode 22 in the device, and another part adheres to the surface of the lower layer A1 wiring 25.

Next, after the etching of the alumina film 27 is completed, the AC power supply 20 is turned off.

Next, this wafer 16 is sent to a sputtering device without being exposed to the atmosphere, and then an upper layer Δ1 film is formed.

At this time, even if titanium is attached to the surface of the lower iAl film 25, since titanium is a conductor, there is no problem of increased contact resistance with the upper layer A1 film.

FIG. 4 is a partial cross-sectional view of a chain contact created by patterning the upper layer A1 film thus formed. In the figure, the reference numeral 2 indicates the upper layer AI wiring, and the other reference numerals indicate the same components as those shown in FIG. 3.

This chain contact has 50,000 through holes connected in series between terminals C and D via AI wiring, and the resistance value between C and D is sufficiently low at 10KΩ in this example. value was obtained. In addition, in the case of a conventional example using a wafer holder whose holding frame is made of quartz. The resistance value of the chain contact was 50KΩ.

As described above, the holding frame portion l3 made of titanium in the embodiment of the wooden invention is extremely effective in reducing contact resistance.

Furthermore, titanium is activated by the collision of argon ions and becomes more likely to bond with oxygen, thereby capturing more oxygen in the chamber 17. Therefore, the effect of reducing oxygen in the chamber 17 due to this function is also large.

Furthermore, titanium attached to the anode iti20 and the like has better adhesion to stainless steel than silicon oxide in the conventional example. This also has the effect of reducing dust within the chamber 17.

Incidentally, in the embodiment of the wooden invention, dithane was used as the holding frame portion 13, but other high melting point metals may also be used. especially,
In the case of zirconium, like titanium, it has an oxygen trapping effect, and has the effect of reducing oxygen in chamber 17.
It's more effective.

Further, even if aluminum is used as the holding frame portion 13, there is an effect of reducing oxygen concentration.

Furthermore, if a high melting point metal or aluminum is used for at least the surface exposed to plasma of the shield ring 17a having a cathode function, the effect of reducing residual oxygen and dust will be greater.

[Effects of the Invention] As explained above, according to the semiconductor manufacturing apparatus of the invention, the wafer holding frame is formed of a high melting point metal material, so the wafer holding frame does not become a source of oxides. can be prevented. Therefore, for example, the contact resistance between the lower metal film and the soil metal film formed on the wafer can be reduced.

Further, since dust such as oxides in the chamber can be reduced, the yield of semiconductor devices can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a svanta enoching apparatus according to an embodiment of the present invention, FIG. 2 is a diagram illustrating a wafer holder provided in a svanta enoching apparatus according to an embodiment of the present invention, and FIG. is a cross-sectional view of a part of a wafer to be etched, FIG. 4 is a cross-sectional view of a wafer with chain contacts formed, FIG. 5 is a cross-sectional view of a conventional sputter etching device, and FIG. 6 is a cross-sectional view of a conventional spatter etching device. , for conventional Svanta etching equipment? It is a figure explaining the obtained wafer holding shell. [Explanation of symbols] 1... Holding base portion, 2... Holding frame portion (quartz glass), 3.14... Wafer placement surface, 4.15... Support rod, 6 17... chamber, 6a, . 17a...shield ring, 7, l8...
Exhaust port, 8.19...Gas inlet port, 9,20...Anode electrode, 9a. 20a... Insulating ring, 10.21... Wafer holder, 11.22... AC power supply, l3... Holding frame (titanium), 2a, 13a... Wafer support pin, 2 3. ...Si2coil film, 24...SiO2 film, 25...Lower layer AI wiring, 26...PSG film, 27...Alumina film, 28...Upper layer A1 cotton distribution.

Claims (2)

[Claims] (1) A chamber, an electrode of one polarity provided in the chamber, and a wafer holding base portion on which a wafer is placed, which is paired with the electrode of one polarity and has an electrode function of another polarity. . A semiconductor manufacturing apparatus comprising: a holding frame made of a high melting point metal or aluminum attached to the wafer holding base for locking the wafer. (2) A semiconductor manufacturing apparatus characterized in that the high melting point metal according to claim 1 is titanium or zirconium.