JPS6015929A - Processor - Google Patents

Abstract

PURPOSE:To enable to avoid adhesion of foreign matters to targets to be generated according to etching of holders or the adhered matters on the surfaces of the holders by a method wherein the holders are made to be in a noncontact condition to a plasma atmosphere. CONSTITUTION:When plasma is formed according to glow discharge in a shutter 12 closed condition, a bias voltage is applied to holders 6 according to a bias electric power source 11. Accordingly, Ar ions formed according to plasma are attracted to collide against wafers 5, and aluminum oxide films of first layer wirings formed on the wafers 5 on the surfaces of through holes are etched or destroyed. Because the main surfaces of the holders 6 are almost covered with the wafers 5, even when foreign matters are adhered on the main surfaces of the holders 6, it offers no problem, and moreover, no ion collides against the holders 6. Moreover, because a masking shield 8 is arranged at the sides of the holders 6, creeping-in of ions to collide against the sides, the backs of the holders 6 and a beam 7, etc. is not generated, too.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a processing technology, particularly a technology in which processing is performed using a plasma phenomenon, and is applicable to, for example, a sputter etching device equipped with a sputter etching function. Concerning effective techniques.

[Background Art] When forming multilayer wiring on a wafer in the manufacture of semiconductor devices, when trying to connect a second layer wiring to a first layer wiring made of aluminum through a through hole, the first layer wiring
Since an oxide film is easily formed on the surface of the through-hole of the layer wiring, there is a problem in that the electrical resistance at the connection between the two wirings becomes large, and as a countermeasure to this problem, it is possible to apply a sputtering device.

In other words, it is conceivable to use a technique in which the oxide film on the surface of the through-hole of the first layer wiring is removed by sputter etching immediately before sputtering the second layer wiring.

However, in such technology, molybdenum (MO),
The holder made of titanium (Ti), aluminum (A1), etc. and the deposits on the holder surface are also sputter-etched together with the wafer, and the resulting substances adhere to the wafer as foreign matter, resulting in swelling and peeling defects in sputtering film formation. The present inventor has discovered that there is a problem in that this occurs.

[Object of the Invention] An object of the present invention is to provide a processing technique that can avoid adhesion of foreign matter to an object due to etching of the holder or the surface adhesion of the holder.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

That is, the holder is kept out of contact with the plasma atmosphere so that the holder and the deposits on the surface of the holder are not etched.

[Embodiment 1] FIG. 1 is a longitudinal cross-sectional view showing a spankling device according to an embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view.

In this embodiment, this sputtering apparatus is equipped with a chamber 1, and this chamber 1 contains argon (Ar).
) and the like, and an exhaust path 3 for evacuating the inside of the chamber to a high vacuum are formed. A rotating shaft 4 rotated by a drive device (not shown) is inserted into the chamber 1, and a holder 6 for holding a wafer 5 as a processing object in a mounted state is mounted on the rotating shaft 4.
are arranged in a radial ring shape, and each is fixed via a beam 7. The plurality of holders 6 are formed into substantially the same disk shape as the wafer 5, and when the wafer 5 is placed thereon, the main surfaces thereof are covered with the wafer. The holder 6 is made of stable metal such as MOLTi.

A shielding plate 8 is fixed to the rotating shaft 4 so as to be electrically insulated by an appropriate means such as interposing an insulating material 10 so as to rotate together, and the shielding plate 8 has a transparent plate that accommodates each holder 6. A plurality of holes 9 are bored.

Therefore, the outer circumference of the holder 6 is shielded by the shielding plate 8.

A bias power source 11 such as a high frequency power source is connected to the rotating shaft 4, so that a bias voltage is applied to the holder 6.

A shutter 12 is provided above the shielding plate 8, and a cathode electrode 13 is provided at a predetermined position above the shutter 12. This electrode 13 is connected to a DC or high frequency power source 14.
is connected to this electrode 13, and aluminum (A
A target 15 such as I) is attached.

Next, the effect will be explained.

In the sputter etching apparatus according to the above configuration, when sputter etching is performed on the through holes of the first layer wiring made of A1 on the wafer, when the wafer 5 is placed on each holder 6, the wafer 5 is placed on each holder 6. The main surface is now covered with the wafer 5.

When plasma is generated by glow discharge with the shutter 12 closed, the bias power supply 11 causes the holder 6 to
A bias voltage is applied to. As a result, Ar ions generated by the plasma are attracted to and collide with the wafer 5, and due to this collision, the aluminum oxide film on the surface of the through hole in the first layer wiring formed on the wafer 5 is etched or Destroyed.

At this time, since the main surface of the holder 6 is almost covered by the wafer 5, there is no problem even if foreign matter adheres to the main surface of the holder 6, and even if a bias voltage is applied, the boulder 6 ions do not collide with each other. In addition, since a shielding plate 8 is arranged on the side of the holder 6,
Ions do not go around and collide with the side and back surfaces of the holder 6, the beam 7, etc. Furthermore, since the shielding plate 8 is electrically insulated and no bias voltage is applied thereto, ions are not attracted to it.

Therefore, the ions do not collide with the boulder 6, the beam 7, or the shielding plate 8 other than the wafer 5, and the phenomenon in which foreign matter generated by this collision adheres to the surface of the wafer 5 can be avoided. As a result, problems such as swelling and peeling of the film due to adhesion of foreign matter during the sputter etching process can be avoided.

Next, the application of the bias voltage by the power supply 11 is canceled, and
When the electrode 13 is energized from the power supply 14 and the shank 12 is opened, the target 1 is
Sputtered atoms are ejected from the wafer 5, thereby sputtering an AI film that will become the second layer wiring on the wafer 5.

At this time, since the AI oxide film in the through-holes of the first layer wiring has been removed by the sputter etching process as described above, the electrical connection between the 1M and 2N AI films can be properly performed. become.

During the sputter etching process and sputter film forming process, the wafer 5 is rotated by the rotating shaft 4 so that the process is uniformly carried out [Example 2] FIG. 3 shows a sputtering process according to another example of the present invention. FIG. 2 is a longitudinal cross-sectional view showing the device.

In this embodiment, an Ar gas introduction path 2 and an exhaust path 3 are formed in the chamber 1, and a rotating shaft 4 is inserted therein. A holder 6A made of a metal such as Mo or Ti and formed into a substantially disk shape is fixed substantially horizontally to the rotating shaft 4.
The upper surface, which is the main surface of this holder 6A, is made of quartz (S i
A covering plate 16 made of a material such as 02) that has almost no adverse effect on sputtering film forming processing and having substantially the same shape as the boulder 6A is removably abutted thereon.

A bias power supply 11 is connected to the rotating shaft 4, and the holder 6A
A DC or high frequency power source 14 is connected to a cathode electrode 13 disposed above the shutter 12 with the shutter 12 in between. An A1 target 15 is attached to the electrode 13.

Next, the effect will be explained.

In the spuck ring apparatus having the above configuration, when the spuck etching process is performed on the through holes of the first layer wiring made of AI on the wafer, the covering plate 16 is laid on the main surface of the holder 6A, and the covering plate 16 A plurality of wafers 5 are placed thereon in an annular arrangement.

When plasma is generated by glow discharge with the shutter 12 closed, a bias voltage is applied to the holder 6A by the power source 11. As a result, Ar ions generated by the plasma are attracted to the wafer 5 and collide with it, and this collision causes the first film to be formed on the wafer 5.
The aluminum oxide film on the surface of the through ball in the layer wiring is subjected to sputter etching treatment.

At this time, the Ar ions also collide with the covering plate 16 on the holder 6A, but since the main surface of the holder 6A is covered with this, there is no collision of Ar ions.

Therefore, no foreign matter is generated from the holder 6A due to ions (h bumps), and the phenomenon of foreign matter from the holder adhering to the surface of the wafer 5 is avoided.

On the other hand, sputtered atoms are ejected from the covering plate 16 by the ion collision, and these also adhere to the surface of the wafer 5. However, since the covering plate 16 is made of 5i02 or the like, it does not have an adverse effect on the spuck film forming process, which will be described later. As a result, problems such as swelling and peeling of the film due to adhesion of foreign matter during the sputter etching process can be prevented.

Next, the application of the bias voltage by the power supply 11 is canceled, and
When the electrode 13 is energized from the power source 14 and the shafter 12 is opened, the target 1 is blown by Ar ions generated by the plasma.
Sputtered atoms are ejected from the wafer 5, thereby forming an A1 film on the wafer 5 by sputtering, which will become the second layer wiring.

At this time, A1 on the surface of the through hole of the first layer wiring
Since the oxide film is removed by the sputter etching process as described above, the AI between the first layer wiring and the second layer wiring is
Electrical connection between the deposited films will be properly made.

Incidentally, during the sputter etching process and the spuck film forming process, the wafer 5 is rotated by the rotating shaft 4 so that the process is performed uniformly.

Furthermore, since a film is also formed on the surface of the covering plate during the sputtering film forming process, it is desirable to clean the covering plate from time to time by replacing it or the like.

[Effects] (1) By making the holder non-contact with the plasma atmosphere, it is possible to avoid collision of ions with the holder, and therefore it is possible to prevent foreign matter generated by this collision from adhering to the object.

(2) By forming the main surface of the holder in the same shape as the object, the holder is covered with the object, thereby preventing ions from colliding with the holder.

(3) By covering the main surface of the holder with a covering plate,
The collision of ions into the boulder can be avoided.

(4) By covering the main surface of the holder with a quartz plate or the like, it is possible to avoid adverse effects on the processing when sputtered atoms are knocked out from the covering plate by ion collisions and adhere to the object to be processed.

Although the invention made by the present inventor has been specifically explained based on Examples above, the present invention is not limited to the above-mentioned Examples, and it is understood that various changes can be made without departing from the gist of the invention. Needless to say.

For example, the shield plate is for preventing ions from going around, so it can be omitted, and the rotation by the rotating shaft is also for uniformity, so it can be omitted.

The covering plate is not limited to 5i02, but can be made of alumina (A1203) or the like.

[Field of Application] In the above explanation, the invention made by the present inventor was mainly applied to a sputtering device having a sputter etching function, which is the field of application in which the invention was made, but the present invention is not limited thereto. (For example, it can also be applied to an apparatus equipped with a reactive ion etching function.

Furthermore, although the present invention has been described as being applied to an apparatus that can process a plurality of wafers, it can also be applied to an apparatus that processes single wafers.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the present invention, FIG. 2 is a half-year cross-sectional view thereof, and FIG. 3 is a longitudinal cross-sectional view showing another embodiment of the present invention. ■...Chamber, 2...Gas introduction path, 3...Exhaust path, 4...Rotation shaft, 5...Wafer (processing target),
6.6A...Holder, 7...Beam, 8...Shielding plate, 9...Through hole, 10...Insulating material, 11...Bias power supply, 12...Shutter, 13... ...Cathode electrode, 14...Power source, 15...Target, 16...
・Covering board.

Claims (1)

[Scope of Claims] 1. A processing apparatus that processes a processing target held in a holder by using a plasma phenomenon, characterized in that the holder is configured to be non-contact with the plasma atmosphere. processing equipment. 2. The processing apparatus according to claim 1, wherein the main surface of the holder is formed in substantially the same shape as the object to be processed. 3. The processing apparatus according to claim 1, wherein the main surface of the holder is coated with a substance that can avoid affecting the processing. 4. The processing apparatus according to claim 1, wherein the substance whose influence on the processing can be avoided is quartz.