US-12622203-B2 - Wafer cleaning method and wafer cleaning system

US12622203B2US 12622203 B2US12622203 B2US 12622203B2US-12622203-B2

Abstract

A wafer cleaning method includes steps as follows. A wafer including a surface to be washed is provided. A first nozzle and a second nozzle disposed above the surface to be washed are provided. The wafer is rotated. A first fluid and a second fluid are provided to spray onto the surface to be washed respectively through the first nozzle and the second nozzle. The first nozzle and the second nozzle are controlled to move a predetermined distance from a central region of the surface to be washed along a first direction away from the central region. The first nozzle and the second nozzle are controlled to move along a second direction opposite to the first direction to a peripheral region of the surface to be washed.

Inventors

Wan Fu Lan
Rong Xin Xu
Wen Yi Tan

Assignees

United Semiconductor (Xiamen) Co., Ltd.

Dates

Publication Date: 20260505
Application Date: 20241027
Priority Date: 20240927

Claims (16)

1 . A wafer cleaning method, comprising: providing a wafer comprising a surface to be washed; providing a first nozzle and a second nozzle disposed above the surface to be washed; rotating the wafer; providing a first fluid onto the surface from the first nozzle, wherein the first fluid is a gas; providing a second fluid onto the surface from the second nozzle, wherein the second fluid is a cleaning liquid; controlling the first nozzle to eject the gas onto a central region of the wafer while the second nozzle ejects the cleaning liquid onto the central region and while the combination of the first nozzle and the second nozzle is located at a first position, wherein the first position of said combination is a position wherein the first nozzle is closer to a center point of the wafer than the second nozzle; performing a first movement of the first and second nozzles such that the combination of the first and second nozzles moves a predetermined distance from the first position to a second position, wherein the predetermined distance is less than a radius of the wafer, wherein the first movement moves the first nozzle away from the center point of the wafer wherein the first movement moves the combination of the first and second nozzles in a first direction, and wherein the second nozzle ejects the cleaning liquid during the first movement; stopping movement of the combination of the first and second nozzles in the first direction once the combination reaches the second position; performing a second movement of the first and second nozzles such that the combination of the first and second nozzles is moved from the second position, wherein the second movement moves the combination of the first and second nozzles in a second direction that is opposite to the first direction, and wherein the second movement comprises the second nozzle ejecting the cleaning liquid onto the wafer throughout a scan of the second nozzle from the central region to a peripheral edge of the wafer.
2 . The wafer cleaning method of claim 1 , wherein there is a spaced distance between the first nozzle and the second nozzle, and the predetermined distance is a half of the spaced distance.
3 . The wafer cleaning method of claim 1 , wherein the gas is a gas for drying the surface to be washed.
4 . The wafer cleaning method of claim 3 , wherein a hydrophobic substance is disposed on the surface to be washed, and the cleaning liquid is a polar cleaning liquid.
5 . The wafer cleaning method of claim 1 , wherein the wafer cleaning method further comprises: controlling the combination of the first nozzle and the second nozzle to stay at the second position for a predetermined period.
6 . The wafer cleaning method of claim 5 , wherein the predetermined period is 3 seconds to 8 seconds.
7 . The wafer cleaning method of claim 1 , wherein before providing the first fluid and the second fluid onto the surface to be washed, the wafer cleaning method further comprises: spraying a cleaning liquid onto the central region of the surface to be washed.
8 . The wafer cleaning method of claim 1 , wherein a moving rate of the first nozzle is identical to a moving rate of the second nozzle.
9 . The wafer cleaning method of claim 1 , wherein a rotating speed of the wafer is 2000 rpm to 2500 rpm, and a moving rate of the first nozzle is 160 mm/s to 240 mm/s.
10 . A wafer cleaning system, comprising: a holder for holding a wafer, wherein the wafer comprises a surface to be washed; a first nozzle disposed above the surface to be washed; a second nozzle disposed above the surface to be washed; and a fluid supply module connected with the first nozzle and the second nozzle; and a control module connected with the holder, the first nozzle, the second nozzle and the fluid supply module, the control module configured to: rotate the holder to bring the wafer to rotate therewith; control the fluid supply module to provide a first fluid to the first nozzle, wherein the first fluid is a gas; control the fluid supply module to provide a second fluid to the second nozzle, wherein the second fluid is a cleaning liquid; control the first nozzle to eject the gas onto a central region of the wafer while the second nozzle ejects the cleaning liquid onto the central region and while the combination of the first nozzle and the second nozzle is located at a first position, wherein the first position of said combination is a position wherein the first nozzle is closer to a center point of the wafer than the second nozzle while the wafer is held by the holder; control a first movement of the first and second nozzles such that the combination of the first and second nozzles moves a predetermined distance from the first position to a second position, wherein the predetermined distance is less than a radius of the wafer, wherein the first movement moves the first nozzle away from the center point of the wafer, wherein the first movement moves the combination of the first and second nozzles in a first direction, and wherein the second nozzle ejects the cleaning liquid during the first movement; stop movement of the combination of the first and second nozzles in the first direction once the combination reaches the second position; control a second movement of the first and second nozzles such that the combination of the first and second nozzles is moved from the second position, wherein the second movement moves the combination of the first and second nozzles in a second direction that is opposite to the first direction, and wherein the second movement comprises the second nozzle ejecting the cleaning liquid onto the wafer throughout a scan of the second nozzle from the central region to a peripheral edge of the wafer.
11 . The wafer cleaning system of claim 10 , wherein there is a spaced distance between the first nozzle and the second nozzle, and the predetermined distance is a half of the spaced distance.
12 . The wafer cleaning system of claim 10 , wherein the gas is a gas for drying the surface to be washed.
13 . The wafer cleaning system of claim 12 , wherein a hydrophobic substance is disposed on the surface to be washed, and the cleaning liquid is a polar cleaning liquid.
14 . The wafer cleaning system of claim 10 , wherein the control module is further configured to: control the combination of the first nozzle and the second nozzle to stay at the second position for a predetermined period.
15 . The wafer cleaning system of claim 14 , wherein the predetermined period is 3 seconds to 8 seconds.
16 . The wafer cleaning system of claim 10 , wherein a moving rate of the first nozzle is identical to a moving rate of the second nozzle.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present disclosure relates to the field of semiconductor devices, and more particularly, to a wafer cleaning method and a wafer cleaning system. 2. Description of the Prior Art In the field of semiconductors, semiconductor devices may be obtained by applying a plurality of semiconductor processes to a wafer, such as doping processes, deposition processes, developing processes, etching processes and planarization processes. After some of the semiconductor processes are completed, the substances used in the semiconductor processes may remain on the surface of the wafer, such as the etching liquid of the etching process and the photoresist of the development process. Therefore, it is necessary to clean the wafer to keep the surface of the wafer clean. In general, a liquid spray device can be used to spray the cleaning liquid, such as a specific acidic solution, alkaline solution or deionized water, onto the surface of the wafer, and then the wafer is rotated to remove the residue and the cleaning liquid on the surface of the wafer. However, the centrifugal force at the center of the wafer is much smaller than the centrifugal force in the periphery of the wafer. Accordingly, the residue located at the center of the wafer is not easily removed, which affects the properties and yield of the semiconductor device subsequently formed. SUMMARY OF THE INVENTION According to an embodiment of the present disclosure, a wafer cleaning method includes steps as follows. A wafer including a surface to be washed is provided. A first nozzle and a second nozzle disposed above the surface to be washed are provided. The wafer is rotated. A first fluid and a second fluid are provided to spray onto the surface to be washed respectively through the first nozzle and the second nozzle. The first nozzle and the second nozzle are controlled to move a predetermined distance from a central region of the surface to be washed along a first direction away from the central region. The first nozzle and the second nozzle are controlled to move along a second direction opposite to the first direction to a peripheral region of the surface to be washed. According to another embodiment of the present disclosure, a wafer cleaning system includes a carrier, a first nozzle, a second nozzle, a fluid supply module and a control module. The carrier is for carrying a wafer, wherein the wafer includes a surface to be washed. The first nozzle is disposed above the surface to be washed. The second nozzle is disposed above the surface to be washed. The fluid supply module is connected with the first nozzle and the second nozzle. The control module is connected with the carrier, the first nozzle, the second nozzle and the fluid supply module. The control module is configured to rotate the carrier to bring the wafer to rotate therewith, control the fluid supply module to provide a first fluid and a second fluid to spray onto the surface to be washed respectively through the first nozzle and the second nozzle, control the first nozzle and the second nozzle to move a predetermined distance from a central region of the surface to be washed along a first direction away from the central region, and control the first nozzle and the second nozzle to move along a second direction opposite to the first direction to a peripheral region of the surface to be washed. These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a wafer cleaning system according to an embodiment of the present disclosure. FIG. 2, FIG. 3, FIG. 4 and FIG. 5 are schematic diagrams showing steps of a wafer cleaning method according to an embodiment of the present disclosure. FIG. 6 is a flow chart showing steps of a wafer cleaning method according to an embodiment of the present disclosure. DETAILED DESCRIPTION In the following detailed description of the embodiments, reference is made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration specific embodiments in which the disclosure may be practiced. In this regard, directional terminology, such as up, down, left, right, front, back, bottom or top is used with reference to the orientation of the Figure(s) being described. The elements of the present disclosure can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. In addition, identical numeral references or similar numeral references are used for identical elements or similar elements in the following embodiments. Hereinafter, for the description of “the first feature is formed on or above the second feature”, it may refer that “the