CN-122028679-A - Semiconductor wafer cleaning system and semiconductor wafer cleaning method

CN122028679ACN 122028679 ACN122028679 ACN 122028679ACN-122028679-A

Abstract

The application relates to the technical field of semiconductor manufacturing. In particular to a semiconductor wafer cleaning system and a semiconductor wafer cleaning method. The semiconductor wafer cleaning system comprises a cleaning liquid supply system and a cleaning and drying integrated chamber, wherein the cleaning liquid supply system is suitable for supplying supercritical carbon dioxide cleaning liquid to the cleaning and drying integrated chamber, the chamber comprises a chamber shell, a wafer supporting module, cleaning liquid spray pipes, drying heating pipes and a main heating component, the chamber shell is communicated with the cleaning liquid supply system, the cleaning liquid spray pipes are distributed on at least one side of the inner wall of the chamber shell and are suitable for spraying supercritical carbon dioxide supplied by the cleaning liquid supply system to a wafer, the drying heating pipes are distributed on at least one side of the inner wall of the chamber shell and are suitable for heating the temperature in a chamber space to maintain the supercritical state of the carbon dioxide stable, and the main heating component is suitable for heating the ambient temperature in the chamber space to dry the wafer after cleaning. The application utilizes supercritical carbon dioxide to clean the wafer, and completes the cleaning and drying steps in one chamber, thereby being efficient and not easy to leave marks.

Inventors

Zhou Zhiman
SUN GANG
LIU HUAN
ZHU MENGLEI

Assignees

北京晶亦精微科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (10)

1. A semiconductor wafer cleaning system, comprising: A cleaning liquid supply system and a cleaning and drying integrated chamber; the cleaning liquid supply system is suitable for supplying supercritical carbon dioxide cleaning liquid to the cleaning and drying integrated chamber; The cleaning and drying integrated chamber comprises: a chamber housing enclosing a closed chamber space and communicating with the cleaning solution supply system; the wafer supporting module is suitable for fixing a wafer to be cleaned and dried in the cavity space and driving the wafer to rotate; The cleaning solution spray pipes are distributed on at least one side of the inner wall of the chamber shell and are suitable for spraying supercritical carbon dioxide cleaning solution supplied by the cleaning solution supply system to the wafer; the drying heating pipes are distributed on at least one side of the inner wall of the chamber shell and are suitable for controlling the temperature in the chamber space so as to maintain the stability of the supercritical state of carbon dioxide; and a main heating part adapted to heat the temperature of the atmosphere in the chamber space to dry the wafer after cleaning.
2. The semiconductor wafer cleaning system of claim 1, wherein, The pipe orifice of the cleaning spray pipe exceeds the pipe orifice of the drying heating pipe; The cleaning solution spray pipes and the drying heating pipes are uniformly distributed on the surface of the drying heating pipe, a plurality of layers of concentric rings are distributed outwards from the center, the number of the cleaning solution spray pipes in each concentric ring is equal to or greater than 2, and the cleaning solution spray pipes and the drying heating pipes are also arranged in the center of the surface of the cleaning solution spray pipes and the drying heating pipe.
3. The semiconductor wafer cleaning system of claim 1, wherein, The wafer support module is a stand-type chuck module, comprising: the clamping jaws are suitable for clamping the wafer in a clamping manner and are distributed relatively; The wafer supporting device comprises a supporting frame and a supporting column, wherein the supporting frame comprises a connecting frame and the supporting column, the connecting frame is connected with the clamping jaw and the supporting column, the supporting column is suitable for rotating and driving the connecting frame and the clamping jaw to rotate so as to drive the wafer to rotate, the connecting frame is of a dispersed connecting rod structure, spaces are arranged between adjacent connecting rods, and the surface of the wafer facing one side of the supporting frame is exposed.
4. The semiconductor wafer cleaning system of claim 1, wherein, The cleaning liquid supply system comprises a balance mixing bin, wherein the balance mixing bin is suitable for mixing carbon dioxide and other components, and is used for heating and pressurizing to form supercritical carbon dioxide cleaning liquid; The other components comprise a cosolvent, a surfactant and other auxiliary agents; The cleaning liquid supply system further comprises a carbon dioxide supply source, a cosolvent supply source, a surfactant supply source and other auxiliary agent supply sources, the balance mixing bin is communicated with the auxiliary agent supply sources through supply pipelines respectively, and each supply pipeline is provided with a stop valve.
5. The semiconductor wafer cleaning system of claim 4, wherein, The balance mixing bin comprises a mixing pool and a circulating pipeline, the circulating pipeline is provided with a circulating pump, and the mixing pool is suitable for heating and pressurizing; The other components are suitable for circulating flow in the balance mixing bin through the circulating pipeline and the circulating pump, and mixing with carbon dioxide in the mixing pool under the heating and pressurizing environment to form supercritical carbon dioxide cleaning liquid; the balance mixing bin is communicated with the cleaning and drying integrated cavity, is communicated with the cleaning liquid spray pipe, and is provided with a throttle valve through a pipeline communicated with the cleaning and drying integrated cavity.
6. The semiconductor wafer cleaning system of claim 1, wherein, The semiconductor wafer cleaning system is also provided with a discharge pipeline which is connected with the cleaning and drying integrated chamber; The exhaust pipeline is communicated with the cavity space and is provided with a back pressure valve so as to discharge carbon dioxide in the cleaning and drying integrated cavity when needed.
7. A method for cleaning a semiconductor wafer is characterized in that, Use of the semiconductor wafer cleaning system of any one of claims 1-6, comprising the steps of: preparing a cleaning solution, and forming a supercritical carbon dioxide cleaning solution in the cleaning solution supply system; Preparing a chamber, namely placing a wafer to be cleaned into the cleaning and drying integrated chamber, performing vacuum treatment on the space in the cleaning and drying integrated chamber, and then heating and pressurizing the space in the cleaning and drying integrated chamber to ensure that the environment in the space of the chamber meets the supercritical condition of supercritical carbon dioxide; Supplying a cleaning solution, wherein the cleaning solution supply system supplies supercritical carbon dioxide cleaning solution to the cleaning and drying integrated chamber; the wafer is cleaned, the wafer is driven to rotate, the cleaning liquid spray pipe sprays supercritical carbon dioxide cleaning liquid to the wafer for cleaning, and the drying heating pipe maintains the temperature in the cleaning process, so that the supercritical carbon dioxide is maintained in a supercritical state; And drying the wafer, wherein the cleaning liquid supply system supplies supercritical carbon dioxide to the cleaning and drying integrated chamber, the drying heating pipe controls the temperature, the supercritical state of the supercritical carbon dioxide is maintained, and the main heating part promotes the temperature of the space in the chamber and dries the surface of the wafer.
8. The method for cleaning a semiconductor wafer according to claim 7, it is characterized in that the method comprises the steps of, The cleaning solution preparation step comprises the following steps: Heating and pressurizing the balance mixing bin to meet the supercritical state requirement of carbon dioxide; providing carbon dioxide to the balance mixing bin through a carbon dioxide supply source, providing other components to the balance mixing bin through other component supply sources, circularly flowing the other components in the balance mixing bin, and mixing the other components with the carbon dioxide in a heating and pressurizing environment to form a supercritical carbon dioxide cleaning solution; the other components comprise a cosolvent, a surfactant and other auxiliary agents.
9. The method for cleaning a semiconductor wafer according to claim 8, it is characterized in that the method comprises the steps of, The supercritical carbon dioxide cleaning liquid comprises a first cleaning liquid, a second cleaning liquid and a third cleaning liquid which are of three different components; The process for cleaning the wafer at least comprises the following steps: Cleaning the surface of the wafer by using a first cleaning liquid to reduce the surface tension of the wafer and reduce the adsorption force on surface particles, wherein the first cleaning liquid is a mixture of supercritical carbon dioxide and a surfactant; Cleaning the surface of the wafer by using a second cleaning liquid to enhance the solubility of pollutant particles on the surface of the wafer, wherein the second cleaning liquid is a mixture of supercritical carbon dioxide and a cosolvent; and cleaning the surface of the wafer by using a second cleaning solution to rinse and remove the pollutant particles on the surface of the wafer, wherein the third cleaning solution is a mixture of supercritical carbon dioxide and a cleaning agent.
10. The method for cleaning a semiconductor wafer according to claim 9, it is characterized in that the method comprises the steps of, In the step of chamber preparation, the temperature in a chamber space of the cleaning and drying integrated chamber is heated to 40-200 ℃, the pressure is pressurized to 8-16 MPa, and the temperature is maintained for at least 10min; In the step of supplying the cleaning liquid, the initial flow rate of the supercritical carbon dioxide cleaning liquid is 2L/min, the initial flow rate is adjusted to 5L/min after 10s, the initial flow rate is adjusted to 10L/min after 10s, and the cleaning liquid is purged into the chamber for 10min through the cleaning liquid spray pipe; in the step of cleaning the wafer, the flow rate of each cleaning liquid spray pipe is 1L/min-4L/min, the pipe orifice is 8mm away from the surface of the wafer, the rotating speed of the wafer is 500rpm, the cleaning time of the first cleaning liquid is 60 s-120 s, the cleaning time of the second cleaning liquid is 60 s-120 s, the cleaning time of the third cleaning liquid is 60 s-120 s, and the temperature in the cavity space of the cleaning and drying integrated cavity is maintained at 40 ℃ to 200 ℃ and the pressure is maintained at 8 to 16MPa in the cleaning process; In the step of drying the wafer, the flow rate of the supercritical carbon dioxide sprayed into the cavity space by the cleaning liquid spray pipe is 1L/min-4L/min, the temperature in the cavity space of the cleaning and drying integrated cavity is maintained at 40-200 ℃, the pressure is maintained at 8-16 MPa, and the drying time is 1-10 min.

Description

Semiconductor wafer cleaning system and semiconductor wafer cleaning method Technical Field The application relates to the technical field of semiconductor manufacturing. In particular to a semiconductor wafer cleaning system and a semiconductor wafer cleaning method. Background In the semiconductor manufacturing process, the conventional cleaning and drying process is difficult to meet the requirements of the fine circuit patterns, and the nondestructive cleaning of the wafer cannot be effectively realized. Because the surface tension of water is large, when the surface film layer material of the wafer is hydrophobic, the deep layer of the electronic circuit pattern with high depth-to-width ratio is difficult to penetrate by the solution, so that the effect of liquid phase cleaning is directly affected, and when the line width is below 14nm, the surface of the wafer is dried after wet cleaning, and the high depth-to-width ratio pattern collapse is easily caused by the influence of the surface tension. Especially when cleaning photoresist on the surface of a low-k film interconnected between layers, the low-k material is mostly porous, the device structure is easy to be damaged by plasma ashing and liquid phase cleaning after ashing, the effective dielectric constant of the low-k film is increased after being soaked and absorbed by a water-based solvent for a long time, and further the interconnection resistance and capacitance of the low-k film are also increased, supercritical carbon dioxide (SCCO2) has high solubility to photoresist, a wafer is placed in CO 2 in a supercritical state, and photoresist pollutants on the wafer can be dissolved in CO 2 fluid in the supercritical state. And the supercritical fluid has gas-like diffusivity and liquid-like dissolution capability, which enables them to permeate well into minute spaces and pores, and by adopting SCCO2 fluid treatment method, it can ensure that even very fine structures can be effectively cleaned, and in the supercritical state, there is no obvious liquid-gas interface, so that the influence of surface tension is greatly reduced, and the high aspect ratio pattern of the wafer surface is effectively protected from collapse. However, since the cleaning process generally passes through multiple chambers, the supercritical fluid is unstable (or the supercritical state is difficult to maintain), so that the ambient temperature of the wafer surface is unstable during the process of moving between the multiple chambers, and the supercritical state of SCCO2 is difficult to maintain stable, so that the cleaning imprint is easily left on the wafer surface. Therefore, a solution is needed to solve the problem that the environmental temperature of the wafer surface is unstable during the supercritical carbon dioxide cleaning process, so that cleaning marks are easily left on the wafer surface. Disclosure of Invention Therefore, the application provides a semiconductor wafer cleaning system and a semiconductor wafer cleaning method, which are used for solving the problem that the environmental temperature of the wafer surface is unstable in the process of cleaning the wafer by supercritical carbon dioxide, so that cleaning marks are easy to leave on the wafer surface. In one aspect of the present application, a semiconductor wafer cleaning system is provided, comprising: A cleaning liquid supply system and a cleaning and drying integrated chamber; the cleaning liquid supply system is suitable for supplying supercritical carbon dioxide cleaning liquid to the cleaning and drying integrated chamber; the cleaning and drying integrated chamber comprises: a chamber housing enclosing a closed chamber space and communicating with the cleaning liquid supply system; the wafer supporting module is suitable for fixing a wafer to be cleaned and dried in the cavity space and driving the wafer to rotate; the cleaning solution spray pipes are distributed on at least one side of the inner wall of the chamber shell and are suitable for spraying supercritical carbon dioxide cleaning solution supplied by the cleaning solution supply system to the wafer; the drying heating pipes are distributed on at least one side of the inner wall of the chamber shell and are suitable for controlling the temperature in the chamber space so as to maintain the stability of the supercritical state of carbon dioxide; and a main heating part adapted to heat the temperature of the atmosphere in the chamber space to dry the wafer after cleaning. According to the semiconductor wafer cleaning system provided by the application, through the arrangement of the chamber shell, the wafer supporting module in the chamber shell, the cleaning liquid spray pipe and the drying heating pipe, the cleaning step and the drying step of the wafer can be carried out in one chamber, the environmental temperature of the wafer surface in the cleaning process can be kept stable, obvious temperature change can not occur due t