CN-121992376-A - Gas distributor for ALD apparatus and venting method for growing thin films on wafers by ALD

Abstract

The invention belongs to the technical field of atomic layer deposition equipment, and particularly relates to a gas distributor for ALD equipment and a ventilation method for growing a film on a wafer through ALD. The gas distributor for the ALD equipment is arranged in the reaction chamber and is positioned above the base, the gas distributor comprises a gas inlet and a conveying channel with a conical spiral shape, the gas inlet is communicated with a gas source, one end of the conveying channel is provided with an inlet section communicated with the gas inlet, the other end of the conveying channel is provided with a closed section, the radius of the circumference of the closed section is smaller than that of the circumference of the inlet section, the horizontal height of the closed section is higher than that of the inlet section, the conveying channel is provided with a gas outlet hole along the length direction, and the gas outlet hole faces the base. The gas distributor provided by the invention is used for carrying out an ALD thin film growth process on an 8-inch wafer, and the obtained thin film has high thickness uniformity and good optical uniformity.

Inventors

• Huang Baoxun
• CHEN QI
• HUANG GUANGLEI
• XU JIAQI

Assignees

• 厦门晶耐科技有限公司

Dates

Publication Date

20260508

Application Date

20260312

Priority Date

20260305

Claims (10)

1. 1. The gas distributor comprises a gas inlet and a conveying channel with a conical spiral shape, wherein the gas inlet is communicated with a gas source, one end of the conveying channel is provided with an inlet section communicated with the gas inlet, the other end of the conveying channel is provided with a closed section, the radius of the circumference of the closed section is smaller than that of the circumference of the inlet section, the horizontal height of the closed section is higher than that of the inlet section, and the conveying channel is provided with a gas outlet hole along the length direction, and the direction of the gas outlet hole is opposite to that of the base.
2. 2. A gas distributor for an ALD apparatus according to claim 1, characterized in that the transport channel is circular in cross section.
3. 3. The gas distributor for an ALD apparatus of claim 1, wherein the number of turns of the transfer channel is 3-5.
4. 4. A gas distributor for an ALD apparatus according to claim 3, characterized in that the spacing between adjacent turns of the transport channels is 2-8 cm; preferably, the screw pitch of the conveying channel is 1-5 cm.
5. 5. The gas distributor for an ALD apparatus of claim 1, wherein the gas outlet holes are each 1-5 cm apart.
6. 6. The gas distributor for an ALD apparatus of claim 1, characterized in that the ratio between the aperture of the gas outlet and the diameter of the transport channel is 1 (0.03-0.5); Preferably, the aperture of each air outlet hole is 1-5 mm, and the diameter of each conveying channel is 10-30 mm.
7. 7. The gas distributor for an ALD apparatus of claim 1, wherein the gas source comprises a carrier gas tank, a reaction gas tank, and a metal source precursor tank, the number of carrier gas tanks, reaction gas tanks, and metal source precursor tanks each being independently 1-3; preferably, the gas in the gas carrying tank is argon and/or nitrogen; Preferably, the gas in the reaction gas tank is ammonia gas or ozone; Preferably, the metal source precursor tank contains at least one of an aluminum metal precursor, a titanium metal precursor, a molybdenum metal precursor and a nickel metal precursor.
8. 8. The gas distributor for an ALD apparatus of claim 7, wherein the gas inlets are in communication with a carrier gas tank, a reaction gas tank, and a metal source precursor tank, respectively; A first gas valve is arranged on a communicating pipeline between the gas inlet and the carrier gas tank and used for regulating and controlling the flow of carrier gas entering the conveying channel; a second gas valve is arranged on a pipeline communicated between the gas inlet and the reaction gas tank and used for regulating and controlling the flow of the reaction gas entering the conveying channel; And a third gas valve is arranged on a pipeline communicated between the gas inlet and the metal source precursor tank and used for regulating and controlling the flow of the metal source precursor entering the conveying channel.
9. 9. A ventilation method for growing a film on a wafer by ALD is characterized by comprising the steps of placing the wafer on a base, heating to a set reaction temperature, introducing reaction gas A into a reaction chamber to perform adsorption reaction with the surface of the wafer, introducing inert gas I for purging, introducing reaction gas B into the reaction chamber to perform chemical reaction on the surface of the wafer, and introducing inert gas II for purging, thereby completing a growth cycle of film generation.
10. 10. The method of venting a film grown by ALD on a wafer of claim 9, wherein the wafer has a diameter of 8 inches; Preferably, when the reaction gas A is ammonia gas or ozone, the reaction gas B contains a metal source precursor, or when the reaction gas A contains a metal source precursor, the reaction gas B is ammonia gas or ozone; preferably, the reaction gas A and the reaction gas B are both introduced into the reaction chamber in the form of pulses; Preferably, the inert gas I and inert gas II are each independently argon and/or nitrogen; Preferably, the metal source precursor is at least one of an aluminum metal precursor, a titanium metal precursor, a molybdenum metal precursor and a nickel metal precursor; Preferably, the flow rate of the ammonia gas or ozone is 100-1000 sccm, and the time is 20-40 s; Preferably, when the reaction gas contains a metal source precursor, the reaction gas is introduced in a pulse form by using inert gas III as carrier gas, the introduction flow of the inert gas III is 10-100 sccm, and the time is 0.5-1.0 s.

Description

Gas distributor for ALD apparatus and venting method for growing thin films on wafers by ALD Technical Field The invention belongs to the technical field of atomic layer deposition equipment, and particularly relates to a gas distributor for ALD equipment and a ventilation method for growing a film on a wafer through ALD. Background Atomic Layer Deposition (ALD) technology plays an increasingly important role in the field of semiconductor fabrication. With continued advances in microelectronic processes, ALD technology has become a critical technology for the fabrication of high performance, high reliability micro-nano devices by virtue of its high precision, high uniformity, and excellent control over composition. At present, the process of depositing thin films on 4-inch and 6-inch wafers by an ALD technology has been developed, but when the wafer size is further expanded to 8 inches (with the diameter of 200 mm) or even 12 inches (with the diameter of 300 mm), the radiation heating or resistance heating system of the traditional ALD equipment is difficult to realize temperature control within +/-1 ℃ of the whole wafer, at the moment, the edge area is possibly 2-5 ℃ lower than the center due to longer heat conduction paths, on one hand, the problems of uneven thickness and poor optical performance uniformity are caused due to the fact that the difference of the film growth rate (up to 10% -15%), on the other hand, the problem that the stress distribution of the thin films is uneven due to the temperature gradient, particularly the stress concentration of the edge area is more obvious, firstly, wafer warpage (warping >20 mu m) is caused, the alignment precision of subsequent photoetching is influenced, and secondly, the problem that the thin films are cracked or peeled off due to stress accumulation in the cooling process caused by the fact that the difference of the thermal expansion coefficient of the thin films and the silicon substrate is large is greatly reduced. However, to meet market demands, further improvements in production efficiency and reduced production costs are critical to achieving uniform, repeatable film deposition on 8 inch wafers with ALD equipment. Disclosure of Invention After extensive and intensive studies, the inventors of the present invention have found that, although improving a heating system of an ALD apparatus is a key core point for achieving uniform and repeatable film deposition on a wafer, it is more economically feasible to improve a gas distributor of the ALD apparatus to compensate for the non-uniformity problem caused by the temperature difference on an 8-inch wafer because the heating system has high technical integration level and high disassembly difficulty and, once changed, may bring a series of linkage risks such as process window offset, re-optimization of process parameters, etc. The use of spiral gas distributors in ALD apparatus to provide uniform gas is disclosed, but such planar spiral gas distributors, while providing uniform output gas flow, have limited effectiveness in addressing the growth rate variation problem on 8 inch wafers due to edge heat loss, resulting in deposition grown films on 8 inch wafers that still suffer from non-uniformity in thickness and poor uniformity in optical properties. One of the purposes of the present invention is to provide a new gas distributor for solving the problems of uneven thickness and poor uniformity of optical performance of the thin film deposited on an 8-inch wafer by the existing ALD apparatus. The ALD apparatus includes a reaction chamber and a stage disposed within the reaction chamber for placing a wafer. In order to solve the technical problems, the invention adopts the following technical scheme: The gas distributor for the ALD equipment is arranged in the reaction chamber and is positioned above the base, the gas distributor comprises a gas inlet and a conveying channel with a conical spiral shape, the gas inlet is communicated with a gas source, one end of the conveying channel is provided with an inlet section communicated with the gas inlet, the other end of the conveying channel is provided with a closed section, the radius of the circumference of the closed section is smaller than that of the circumference of the inlet section, the horizontal height of the closed section is higher than that of the inlet section, the conveying channel is provided with a gas outlet hole along the length direction, and the direction of the gas outlet hole is opposite to the base. In some embodiments of the invention, the delivery channel is circular in cross-section. In some embodiments of the present invention, the number of turns of the conveying channel is 3-5. In some embodiments of the present invention, the distance between adjacent turns of the conveying channels is 2-8 cm. In some embodiments of the present invention, the pitch of the conveying channel is 1-5 cm. In some embodiments of the present invention,