TW201416489A - Gas spray head and method for manufacturing the same - Google Patents

Abstract

The present invention provides a gas spray head and a method for manufacturing the same. Said method includes the following steps: installing a plurality of holes with a first aperture on a graphite disk; placing said graphite disk inside a deposition reactor; depositing one layer of silicon carbide on the upper surface and the lower surface of the graphite disk and the inner walls of the first holes; and installing holes with a second aperture inside the holes with the first aperture after carrying out deposition, wherein the second aperture is smaller than the first aperture. By adopting said technique method, the silicon carbide which is not easy to be corroded by plasma can be deposited on the lower surface of the graphite disk and the surface of inner wall of gas inlet holes, thereby prolonging service life of the gas spray head and saving the cost.

Description

Gas shower head and method of making the gas shower head

The present invention relates to the field of manufacturing semiconductor devices, and more particularly to a technical field for fabricating a showerhead that controls the entry of reactive gases into a reaction chamber.

In the manufacturing process of a semiconductor device, such as etching, deposition, oxidation, sputtering, etc., the substrate (semiconductor wafer, glass substrate, etc.) is usually processed by plasma. Generally, a plasma processing apparatus includes a capacitive coupling type plasma reactor and an inductively coupled type plasma reactor as a method of generating plasma in a high frequency discharge type plasma processing apparatus. The capacitive coupling type reactor is generally provided with an upper electrode and a lower electrode, preferably the two electrodes are arranged in parallel. Further, the substrate to be processed is usually placed on the lower electrode, and a high-frequency power source for plasma generation is applied to the upper electrode or the lower electrode via the integrator. The external electrons of the reaction gas are accelerated by the high-frequency electric field generated by the high-frequency power source, and plasma is generated to plasma-treat the lower substrate.

In recent years, in the field of semiconductor manufacturing, a shower head for supplying air to a substrate to be processed has been used. For example, in the plasma etching apparatus, a mounting table for mounting a substrate is disposed in the processing chamber, and a shower head is disposed at a position opposite to the mounting table, and a plurality of gas ejection holes are provided on a surface of the shower head. The reaction gas is supplied in a spray form to generate a plasma. In the plasma processing apparatus described above, since the plasma is generated in the processing chamber, the temperature of the shower head is generally high.

The existing sprinkler head is generally made of aluminum, but the aluminum is easy to be in a plasma environment. Corroded, resulting in a short life of the showerhead. In response to this problem, in the prior art, the outer surface of the substrate is covered with a layer of aluminum oxide (Al 2 O 3 ) which is more resistant to etching than aluminum, however, since the shower head is in contact with the plasma during use, the surface of the alumina It is easy to react with the fluorine-containing plasma to form aluminum fluoride particles, which gradually accumulate to form large particles, which may cause pollution when dropped on the wafer to be etched, and thus alumina is not the preferred material for the shower head cover layer. The industry is gradually replaced by a coating of bismuth (thermal conductivity: 149Wm-1K-1) or strontium carbide (thermal conductivity: 150Wm-1K-1) which is less likely to cause particle contamination and has good heat dissipation performance.

A whole piece of tantalum carbide sprinkler formed by chemical vapor deposition has very good corrosion resistance. However, the sprinkler made by this method is too expensive and not competitive in the market. If the surface of the shower head is coated with tantalum carbide, the plasma outlet will be bombarded due to the high plasma energy, resulting in a decrease in the service life of the shower head.

In order to solve the above problems, the present invention provides a gas shower head and a method of fabricating the gas shower head, the method comprising the steps of: a) providing a plurality of holes of a first aperture on a graphite disk; Depositing the graphite disk in a deposition reactor, depositing a layer of tantalum carbide on the lower surface of the graphite disk and the inner wall of the first small hole; c). A hole of a second aperture is formed in the aperture of the aperture, the second aperture being smaller than the first aperture.

Further, the deposition reaction method is a chemical vapor deposition method, and the deposition reactor is a chemical vapor deposition reactor.

Further, a layer of tantalum carbide is also deposited on the upper surface of the graphite disc.

The first small hole has a diameter ranging from 1 mm to 6 mm, and the second small hole The aperture range is from 0.1 mm to 2 mm.

The upper and lower surfaces of the graphite disk and the thickness of the tantalum carbide deposited on the inner wall of the first small hole are proportional to the reaction gas concentration and reaction time in the chemical vapor deposition reactor.

Further, a layer of ruthenium oxide is deposited on the outside of the tantalum carbide layer, and the ruthenium oxide layer is formed by chemical vapor deposition or plasma enhanced chemical vapor deposition.

Further, the upper surface and the lower surface of the graphite disc have a thickness of the tantalum carbide layer of more than 0.5 mm.

Further, the hole of the first aperture and the hole of the second aperture are evenly distributed on the gas shower head.

Further, the lower end of the hole of the first aperture is fabricated from the surface of the graphite disk near the plasma, and the height of the hole of the first aperture is smaller than the thickness of the graphite disk.

Further, the present invention further provides a gas shower head comprising a graphite disc, the upper and lower surfaces of the graphite disc are coated with a layer of niobium carbide, and the graphite disc is provided with a plurality of small holes. The inner wall of the small hole is coated with a layer of tantalum carbide, and the inner wall of the small hole is coated with a tantalum carbide thickness of more than 0.5 mm.

The method for manufacturing a gas shower head according to the present invention, by making two holes, depositing a large thickness of tantalum carbide which is not easily corroded by plasma, on the upper and lower surfaces of the graphite disk and the inner wall surface of the air inlet hole, thereby extending The use of gas sprinklers simultaneously saves costs.

Other features, objects, and advantages of the invention will be apparent from the description of the accompanying drawings.

10‧‧‧ graphite disc

12‧‧‧ hole

14‧‧‧ hole

20‧‧‧ upper surface

22‧‧‧ Lower surface

24‧‧‧ inner wall surface

312‧‧‧ hole

314‧‧‧ hole

324‧‧‧ inner wall surface

A1‧‧‧ aperture

A2‧‧‧ aperture

Figure 1 shows a plan view of the gas shower head of the present invention; 2 is a schematic view showing the structure of the gas shower head along the A-A section; FIG. 3 is a schematic view showing the gas shower head of another embodiment taken along the A-A section.

Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

The present invention provides a method of fabricating a gas showerhead, the method comprising the steps of: first, a plurality of holes 12 having a first aperture a1 are disposed on a graphite disk 10 for plasma etching of the reactive gas The holes 12 of the first aperture are evenly distributed on the graphite disk 10; of course, the distribution of the holes 12 of the first aperture on the graphite disk 10 may be unevenly distributed according to actual needs. Then, the graphite disk 10 is placed in a deposition reactor, and a layer of tantalum carbide is deposited on the upper surface 20, the lower surface 22 of the graphite disk 10, and the inner wall surface 24 of the hole 12 of the first aperture; finally, the tantalum carbide is completed. A hole 14 having a second aperture a2 is disposed in the hole of the first aperture that is deposited, and the second aperture a2 is smaller than the first aperture a1.

The deposition reactor may be a chemical vapor deposition reactor, and the graphite disk 10 provided with the first aperture hole 12 is placed in a chemical vapor deposition reactor, and the reaction gas in the reactor is on the graphite disk. The surface 20, the lower surface 22, and the inner wall surface 24 of the first aperture hole 12 are grown to a certain thickness of tantalum carbide. Since the technique of depositing tantalum carbide in the chemical vapor deposition reactor is prior art, a large number of patent documents and papers carry out the same. A detailed introduction and description will not be repeated here.

After chemical vapor deposition of the graphite disk, a surface of the inner wall of the hole 12 of the first aperture is deposited with a layer of tantalum carbide, the aperture is small and the surface is not smooth, and a hole 14 of the second aperture is formed at the center of the hole 12 of the first aperture. The first aperture a1 ranges from 1 mm to 6 mm. If the range of the first aperture is too small, the thickness of the deposited tantalum carbide layer is too small, and the range of the first aperture is excessively large, resulting in an excessive spacing of the air inlet holes on the graphite disk; The aperture a2 of the aperture ranges from 0.1 mm to 2 mm. The thickness of the tantalum carbide deposited on the graphite disk upper surface 20, the lower surface 22, and the inner wall surface 24 of the first aperture hole 12 is proportional to the reaction gas concentration and reaction time in the chemical vapor deposition reactor.

After chemical vapor deposition of graphite discs, the upper surface 20 and the lower surface 22 are not only Slip, cut it as needed, and make the surface of the upper surface 20 and the lower surface 22 smooth while ensuring the desired thickness, and the thickness of the lower surface 22 after the cutting is not less than 0.5 mm. In this embodiment, since the graphite material is soft, although the upper surface 20 does not come into contact with the plasma, the upper surface 20 is simultaneously subjected to chemical vapor deposition for ease of mounting.

In order to further improve the service life of the gas shower head, it can be deposited in tantalum carbide After completion, a layer of ruthenium oxide is further deposited, and the ruthenium oxide layer is formed by chemical vapor deposition or plasma enhanced chemical vapor deposition. The ruthenium oxide layer is further doped with at least one of cesium fluoride, ruthenium oxide, ruthenium carbide, ruthenium nitride, zirconium oxide, and aluminum oxide.

Since the plasma can only corrode the portion of the inlet hole near the end of the plasma, In another embodiment, in order to reduce the gas required for the deposition of tantalum carbide, the graphite disk 10 may not be completely penetrated when the first aperture hole 312 is disposed, and then the graphite disk 10 is placed in a deposition reactor in the graphite. The upper surface 20, the lower surface 22 of the disk 10 and the inner wall surface 324 of the hole 312 of the first aperture are deposited with a layer of silicon carbide; finally, a hole 314 of the second aperture is disposed in the hole 312 of the first aperture where the deposition is completed, The second aperture is smaller than the first aperture.

Other technical solutions in this embodiment are the same as those in the foregoing embodiment, and are not described herein.

The present invention is disclosed in the above preferred embodiments, but it is not intended to limit the present invention, and any one skilled in the art can make possible variations and modifications without departing from the spirit and scope of the invention. The scope of protection should be determined by the scope defined by the claims of the present invention.

10‧‧‧ graphite disc

12‧‧‧ hole

14‧‧‧ hole

20‧‧‧ upper surface

22‧‧‧ Lower surface

24‧‧‧ inner wall surface

A1‧‧‧ aperture

A2‧‧‧ aperture

Claims (10)

A method of making a gas showerhead, characterized in that the method comprises the steps of: a) providing a plurality of holes of a first aperture in a graphite disk; b) placing the graphite disk in a deposition reactor, depositing a layer of niobium carbide on the lower surface of the graphite disc and the inner wall of the first aperture; c) forming a second aperture in the hole of the first aperture that is deposited The second aperture is smaller than the first aperture. The method according to claim 1, wherein said deposition reaction method is chemical vapor deposition, and said deposition reactor is a chemical vapor deposition reactor. The method of claim 1 wherein a layer of tantalum carbide is also deposited on the upper surface of said graphite disk. The method of claim 1 wherein said first aperture has a pore size in the range of from 1 mm to 6 mm and said second aperture has a pore size in the range of from 0.1 mm to 2 mm. The method according to claim 1, wherein the upper and lower surfaces of the graphite disk and the thickness of the tantalum carbide deposited on the inner wall of the first small hole and the concentration and reaction of the reaction gas in the chemical vapor deposition reactor Time is proportional. The method according to claim 1, wherein a further layer of ruthenium oxide is deposited on the ruthenium carbide layer, and the ruthenium oxide layer is formed by chemical vapor deposition or plasma enhanced chemical vapor deposition. The method of claim 1 wherein said tantalum carbide layer has a thickness greater than 0.5 mm. The method of claim 1 wherein the apertures of the first aperture and the apertures of the second aperture are evenly distributed over the gas showerhead. The method of claim 1 wherein the lower end of the aperture of the first aperture is fabricated from a surface of a graphite disk adjacent to the plasma, the height of the aperture of the first aperture being less than the thickness of the graphite disk . A gas shower head comprising a graphite disc, the graphite disc is coated with a layer of niobium carbide on the upper and lower surfaces, wherein the graphite disc is provided with a plurality of small holes, the small holes The inner wall is coated with a layer of tantalum carbide, and the inner wall of the small hole is coated with a tantalum carbide thickness of more than 0.5 mm.