CN210349767U - Plasma etching reaction chamber - Google Patents

Abstract

The utility model discloses a plasma etching reaction chamber, including casing, base, first electrode, second electrode, aluminium base board, ceramic plate and sunshade, the inside of casing has a cavity. The base is arranged at the bottom of the chamber, the first electrode is arranged on the base in a disc shape and bears the wafer to be etched, and the aluminum substrate is fixedly arranged on the base and is annularly connected with the upper edge of the peripheral surface of the first electrode. The second electrode is arranged at the upper part of the cavity, the ceramic plate is fixedly arranged at the bottom of the second electrode, the shielding plate is arranged below the ceramic plate and surrounds the ceramic plate to form a plasma chamber, and a plurality of through holes are formed in the shielding plate. The utility model discloses a set up the sunshade that has the through-hole in the below of ceramic plate for on aluminium base board was mostly sputtered the sunshade by the aluminium molecule that the bombardment came out, the aluminium molecule of small part sees through the sunshade and is plated on the ceramic plate but does not influence the induction field that the coil produced and enter into the cavity, forms high density electricity thick liquid between ceramic plate and the sunshade, and the through-hole on this sunshade of electricity thick liquid accessible etches the wafer of below.

Description

Plasma etching reaction chamber

Technical Field

The utility model belongs to the technical field of electric thick liquid etching, in particular to electric thick liquid etching reaction chamber.

Background

During the plasma cleaning process, many byproducts are generated, such as alumina, silicon dioxide, silicon nitride, carbon, organic compounds, contaminant gases, etc. These byproducts will form aerosol particles if they do not adhere effectively to the shield of the plasma cleaning chamber and become suspended in the chamber volume. After the wafer is processed by the plasma cleaning process, these particles will adhere to the wafer, and will be carried out of the plasma cleaning chamber together with the wafer, and proceed the next metal coating. If the particles are attached to the wiring area of the semiconductor wire in the future, the wire will not be conducted, resulting in yield loss.

The method for preventing the generation of the particles is to change the etched substrate into a metal material, usually an aluminum substrate, at a fixed period, bombard the aluminum substrate with argon particles, sputter aluminum molecules on the aluminum substrate onto a shielding plate of a chamber, and adhere the particles on the shielding plate of the chamber. Similarly, if aluminum molecules on the aluminum substrate are sputtered and react with the contamination gas in the chamber, and the sputtered aluminum molecules adhere to the chamber shield, the gaseous byproducts adsorbed on the shield can be covered or react, so that the gaseous byproducts can not contaminate the wires on the wafer surface.

In the ICP fabrication process, ICP high density plasma is generated by using a coil to generate an induced electromagnetic field that can pass through a non-metallic material, such as a ceramic plate, into a chamber to increase the plasma density in the chamber. Once the surface of the ceramic plate is covered by metal, the electromagnetic field cannot penetrate through the ceramic plate, so that the chamber cannot generate high-density plasma. At present, in order to prevent this phenomenon, a lateral coil is usually used in combination with a ceramic dome, and a metal frame is used to shield metal, so as to reduce the amount of metal substances generated by the aluminum substrate plated on the ceramic dome to maintain the generation of high-density plasma. However, the manufacture of the ceramic vault requires much time, the manufacturing cost is high, and the manufacturing process is complex.

Disclosure of Invention

To the above problem, an object of the utility model is to provide a plasma etching reaction chamber sets up foraminiferous sunshade through the below at the ceramic plate for on aluminium base board was sputtered the sunshade by the aluminium molecule majority that the bombardment came out, the aluminium molecule of fractional part sees through the sunshade and is plated on the ceramic plate but does not influence the induction magnetic field that the coil produced and enter into the cavity, and the cost of manufacture of sunshade is low, and the manufacturing process is simple, and the preparation time is short.

In order to realize the purpose, the utility model discloses a technical scheme as follows:

a plasma etching reaction chamber comprises a machine shell, wherein a cavity is arranged in the machine shell, and a process gas inlet is formed in the side edge of the cavity. The etching chamber is characterized by further comprising a base, a first electrode, a second electrode, an aluminum substrate, a ceramic plate and a shielding plate, wherein the base is arranged at the bottom of the chamber, the first electrode is arranged on the base in a disc shape and used for bearing a wafer to be etched, and the aluminum substrate is fixedly arranged on the base and is annularly connected to the upper edge of the peripheral surface of the first electrode. The second electrode is arranged on the upper portion of the cavity, the ceramic plate is fixedly arranged at the bottom of the second electrode, the shielding plate is arranged below the ceramic plate and surrounds the ceramic plate to form a plasma chamber, and a plurality of through holes are formed in the shielding plate.

Furthermore, the shielding plates are provided with a plurality of blocks, and the through holes on any two adjacent shielding plates are arranged in a staggered mode.

In one embodiment, the through holes are straight holes, and the shapes of the straight holes are not limited, and the straight holes can be circular holes, polygonal holes or irregular holes.

In another embodiment, the through hole is a chamfered hole with a gradually increasing diameter from top to bottom, and the chamfer angle of the chamfered hole is 40-89 degrees, so that aluminum molecules bombarded by aluminum metal can be adhered to the bottom of the shielding plate and also can be adhered to the inclined plane of the chamfered hole, and the adhesion area of the shielding plate is increased.

Furthermore, the first electrode is externally connected with a radio frequency power supply, and the second electrode is externally connected with an inductively coupled plasma coil.

Furthermore, a cooling water channel is arranged inside the first electrode, a cooling water pipe communicated with the cooling water channel is arranged below the first electrode, and the cooling water pipe is connected to an external ice and water machine.

Furthermore, an annular caulking groove is formed in the top of the first electrode, and an inner ring of the aluminum substrate is embedded in the caulking groove.

Further, the material of the shielding plate is SiC.

The utility model discloses following beneficial effect has: a shield plate with a through hole is arranged below a ceramic plate, so that most of aluminum molecules bombarded by an aluminum substrate are sputtered on the shield plate, a small part of aluminum molecules are plated on the ceramic plate through the shield plate but do not affect an induction magnetic field generated by a coil to enter a chamber, high-density plasma is formed between the ceramic plate and the shield plate, and the plasma can etch a wafer below through the through hole on the shield plate. The ceramic plates are planar, and the planar ceramic plates are relatively simpler to manufacture than ceramic domes, only need 1/5 of the ceramic domes for cost, and are manufactured in a short time. Because the ceramic plate is planar, it is easier to arrange waterways within the ceramic plate than on a ceramic dome. When the holes on the shielding plate are designed by the chamfer holes, the adhesion area of the shielding plate is increased, and the aluminum adhesion times or cleaning times of the shielding plate are reduced.

Drawings

FIG. 1 is a schematic view of an internal structure of a plasma etching chamber according to an embodiment.

FIG. 2 is a schematic view of the internal structure of the plasma etching chamber according to the second embodiment.

FIG. 3 is a schematic view of the internal structure of a plasma etching chamber according to a third embodiment.

Description of the main component symbols: 1. a housing; 10. a chamber; 100. a plasma chamber; 101. an exhaust port; 102. a process gas inlet; 2. a base; 3. a first electrode; 31. a radio frequency power supply; 32. a cooling water channel; 33. a cooling water pipe; 4. a second electrode; 41. an inductively coupled plasma coil; 5. an aluminum substrate; 6. a ceramic plate; 7. a shutter; 71. a through hole; 72. chamfering holes; 73. a through hole; 8. and (5) a wafer.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the following detailed description.

Example one

As shown in fig. 1, a plasma etching chamber includes a housing 1, a base 2, a first electrode 3, a second electrode 4, an aluminum substrate 5, a ceramic plate 6 and a shielding plate 7, wherein the housing 1 has a chamber 10 therein, an exhaust port 101 is disposed at the bottom of the chamber 10, a process gas inlet 102 is disposed at a side of the chamber 10, and the process gas inlet 102 is externally connected to an argon source.

The base 2 is arranged at the bottom of the chamber 10, the first electrode 3 is arranged on the base 2 in a disc shape and used for bearing a wafer 8 to be etched, the first electrode 3 is externally connected with a radio frequency power supply 31, the top of the first electrode 3 is provided with an annular caulking groove, and the inner ring of the aluminum substrate 5 is embedded in the caulking groove. The first electrode 3 is provided with a cooling water channel 32 inside, a cooling water pipe 33 communicated with the cooling water channel 32 is arranged below the first electrode 3, and the cooling water pipe 33 is connected to an external water chiller (not shown in the figure). The second electrode 4 is disposed at the upper portion of the chamber 10, and the top of the second electrode 4 is externally connected to an inductively coupled plasma coil 41. The ceramic plate 6 is fixed at the bottom of the second electrode 4, the shielding plate 7 is arranged below the ceramic plate 6 and surrounds the ceramic plate 6 to form the plasma chamber 100, the material of the shielding plate 7 is SiC, the shielding plate 7 is provided with a plurality of through holes 71, and the shape of the through holes 71 is not limited and can be a circular hole, a polygonal hole or a special-shaped hole.

In this embodiment, during the plasma cleaning process, the wafer 8 is introduced into the chamber 10 by the external robot and placed on top of the first electrode 3, and argon is introduced into the process gas inlet 102 to raise the pressure in the chamber 10 to a pressure at which the plasma can operate. After the cleaning is started, the plasma bombardment is used to remove the oxide of the aluminum electrode on the wafer 8 and some trace pollutants to perform the plasma cleaning action, and the plasma bombards the aluminum substrate 5 while cleaning the wafer 8, so that the aluminum molecules on the surface of the aluminum substrate 5 are bombarded out and directly combined with the gaseous byproducts, and the gaseous byproducts do not diffuse and contaminate the surface of the wafer 8 during and after the manufacturing process. In addition, these aluminum molecules will also plate on the mask 7 of the chamber 10, only a small portion of the aluminum molecules will pass through the through holes of the mask 7 and plate on the ceramic plate 6, but will not affect the induced magnetic field generated by the coil and enter into the chamber 10, and a high density plasma is formed between the ceramic plate 6 and the mask 7, and the plasma can etch the wafer 8 below through the through holes 71 on the mask 7.

Example two

As shown in fig. 2, the present embodiment is different from the first embodiment only in that: set up the chamfer hole 72 that a plurality of from top to bottom aperture crescent on the sunshade 7, the chamfer angle of chamfer hole 72 is 40 ~ 89 through-holes for aluminium base board 5 by the aluminium molecule of bombarding out both can adhere in sunshade 7 bottom, can also adhere on the inclined plane in chamfer hole 72, increase sunshade 7 adhere the area. The chamfered hole 72 may be provided in a form that is wide at the top and narrow at the bottom, and the embodiment is not limited. The rest of the structure of the present embodiment is the same as that of the first embodiment.

EXAMPLE III

As shown in fig. 3, the present embodiment is different from the first embodiment only in that: the two shielding plates 7 are provided with a plurality of through holes 73, the two shielding plates 7 are respectively provided with a plurality of through holes 73, the through holes 73 can be straight through holes 71 in the first embodiment or chamfered holes 72 in the second embodiment, and the through holes 73 on the upper and lower shielding plates 7 are arranged in a staggered manner. The two shields 7 are arranged for the purpose of: the ceramic plate 6 and the chamber 10 can be completely isolated, and aluminum molecules ejected from the aluminum substrate 5 can be completely plated on the two shields 7. The number of the shielding plates 7 of this embodiment may be larger than two, and is not limited. The rest of the structure of the present embodiment is the same as that of the first embodiment.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (9)

1. A kind of plasma etching reaction chamber, including the chassis, the inside of the said chassis has a cavity, the side of the said cavity has process gas inlets, characterized by that: the etching device comprises a cavity, and is characterized by further comprising a base, a first electrode, a second electrode, an aluminum substrate, a ceramic plate and a shielding plate, wherein the base is arranged at the bottom of the cavity, the first electrode is arranged on the base in a disc shape and used for bearing a wafer to be etched, the aluminum substrate is fixedly arranged on the base and is annularly connected to the upper edge of the peripheral surface of the first electrode, the second electrode is arranged at the upper part of the cavity, the ceramic plate is fixedly arranged at the bottom of the second electrode, the shielding plate is arranged below the ceramic plate and surrounds the ceramic plate to form a plasma chamber, and a plurality of through holes are formed in the shielding plate.

2. A plasma etch chamber as recited in claim 1, wherein: the sunshade be equipped with the polylith, the through-hole setting of staggering each other on two arbitrary adjacent sunshade.

3. A plasma etch chamber as recited in claim 1 or 2, wherein: the through hole is a straight hole.

4. A plasma etch chamber as recited in claim 1 or 2, wherein: the through hole is a chamfer hole with the diameter gradually increasing from top to bottom, and the chamfer angle of the chamfer hole is 40-89 degrees.

5. A plasma etch chamber as recited in claim 1, wherein: the first electrode is externally connected with a radio frequency power supply, and the second electrode is externally connected with an inductively coupled plasma coil.

6. A plasma etch chamber as recited in claim 1, wherein: and a cooling water channel is arranged in the first electrode, a cooling water pipe communicated with the cooling water channel is arranged below the first electrode, and the cooling water pipe is connected to an external water chiller.

7. A plasma etch chamber as recited in claim 1, wherein: the top of the first electrode is provided with an annular caulking groove, and the inner ring of the aluminum substrate is embedded in the caulking groove.

8. A plasma etch chamber as recited in claim 1, wherein: and an exhaust port is arranged at the bottom of the cavity and is connected to an external air suction pump through a pipeline.

9. A plasma etch chamber as recited in claim 1, wherein: the shielding plate is made of SiC.

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