CN111299253B

CN111299253B - Plasma cleaning device

Info

Publication number: CN111299253B
Application number: CN202010162985.3A
Authority: CN
Inventors: 徐俊成; 尹影; 江伟; 庞浩
Original assignee: Beijing Semicore Microelectronics Equipment Co Ltd
Current assignee: Beijing Jingyi Precision Technology Co ltd
Priority date: 2020-03-10
Filing date: 2020-03-10
Publication date: 2022-02-22
Anticipated expiration: 2040-03-10
Also published as: CN111299253A

Abstract

The invention relates to the technical field of integrated circuit manufacturing, in particular to a plasma cleaning device. It is including wasing the cavity, and with the air supply unit who washs the cavity intercommunication, air supply unit to let in clean gas in the washing cavity, make the washing cavity is in the malleation state, avoids outside environmental contaminant to enter into in the washing cavity, realize wasing microenvironment control in the cavity, keep the cleanliness factor grade in the plasma process cavity, reach and avoid wasing piece plasma cleaning back secondary pollution, improve plasma cleaning process effect.

Description

Plasma cleaning device

Technical Field

The invention relates to the technical field of integrated circuit manufacturing, in particular to a plasma cleaning device.

Background

Integrated circuit fabrication processes generally refer to the deposition of conductor, semiconductor, and insulator layers on a particular substrate (e.g., a silicon-based wafer) in a process sequence. In the manufacturing process, a CMP (chemical mechanical polishing) apparatus is mainly used to perform global planarization on a microscopically rough surface of a wafer after a film deposition process in order to perform a subsequent semiconductor process. After the wafer surface is flattened by using CMP, the wafer surface needs to be cleaned to remove various fine particles in the polishing process. In the existing cleaning process, a plasma cleaning process can be used, i.e., the plasma state of a substance is utilized to clean the dirt particles on the surface of the substrate through physical and chemical actions, and the plasma cleaning process can generally determine the process effect of the plasma cleaning through parameters such as energy, temperature, cleaning time and the like. In the prior art, the plasma cleaning device generally adopts an open type cavity or a vacuum cavity, and in the open type cavity or the vacuum cavity, the plasma cleaning can well remove pollutants in the occasions with low cleanliness requirement. For controlling contamination of semiconductor device product grade, there is generally strict requirement for particle size of contamination, such as 0.1 μm ≦ 1 particle @1m³Therefore, even if the contamination of the wafer surface can be removed by the cleaning action of the plasma, it is possible to remove the contamination of the wafer surfaceThe cleaning failure problem can occur because some potential contamination still exists in the plasma cleaning chamber.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the problem that the existing plasma cleaning equipment is ineffective in cleaning, and provide a plasma cleaning device with better cleaning effect.

In order to solve the problems, the plasma cleaning device comprises a cleaning chamber and a gas source device communicated with the cleaning chamber, wherein the gas source device is used for introducing clean gas into the cleaning chamber so as to enable the cleaning chamber to be in a positive pressure state.

Two electrode plates and a supporting bracket are arranged in the cleaning cavity, and the projections of the electrode plates and the supporting bracket on the air source device are positioned in an air outlet of the air source device.

The air source device is a fan filter unit A with an ultra-high efficiency filter.

The fan filter unit A comprises a shell, an air inlet and an air outlet which are arranged on two sides of the shell, wherein a pre-filter is arranged at the air inlet, the ultra-high efficiency filter is arranged at the air outlet, and a fan is arranged between the pre-filter and the ultra-high efficiency filter.

Wherein, the fan is a centrifugal fan.

The supporting bracket is vertically arranged, and the air source device is arranged on the upper side of the cleaning chamber.

The cleaning device comprises a support frame, a cleaning piece and a cleaning cavity, wherein the cleaning device also comprises a process gas inlet arranged on the side wall of the cleaning cavity, and the process gas inlet is positioned on one side of the back surface of the support frame where the cleaning piece is arranged.

The cleaning device comprises a support bracket, a cleaning piece and an electrode plate, wherein the support bracket is arranged on the side wall of the cleaning chamber, and the electrode plate is arranged on the side wall of the support bracket.

Wherein the air outlet and the process gas outlet are respectively positioned at two sides of the cleaning chamber.

The technical scheme of the invention has the following advantages:

1. the plasma cleaning device comprises a cleaning cavity and a gas source device communicated with the cleaning cavity, wherein the gas source device is used for introducing clean gas into the cleaning cavity, so that the cleaning cavity is in a positive pressure state, external environmental pollutants are prevented from entering the cleaning cavity, the control of a microenvironment in the cleaning cavity is realized, the cleanliness grade in the plasma process cavity is kept, secondary pollution after plasma cleaning of a cleaning piece is avoided, and the plasma cleaning process effect is improved.

2. According to the plasma cleaning device, the projections of the electrode plate and the supporting bracket on the air source device are positioned in the air outlet of the air source device, so that the electrode plate and the supporting bracket can be prevented from blocking the blowing of the air source device, and the influence of damage to a cleaning piece on the supporting bracket in the blowing process of the air source device and the like can be avoided.

3. According to the plasma cleaning device, the ultra-high efficiency filter can filter micro particles of gas entering the cleaning chamber, so that secondary pollution of the cleaning piece after plasma cleaning caused by the existing micro particles is avoided.

4. According to the plasma cleaning device, the centrifugal fan can blow air flow out along the circumferential direction, the air flow in the shell can be blown to the ultra-high efficiency filter more smoothly and uniformly, and the damage to the filter caused by the fact that the fan directly blows the ultra-high efficiency filter can be avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic structural diagram of a plasma cleaning apparatus according to the present invention;

description of reference numerals:

1-cleaning the chamber; 2-plasma state; 3-a left electrode plate; 4-a right electrode plate; 5-a support bracket; 6-a shell; 7-air inlet; 8-an ultra-high efficiency filter; 9-a fan; 10-a process gas inlet; 11-process gas outlet; 12-an air outlet; 13-plasma generating means.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

The plasma cleaning device in this embodiment, as shown in fig. 1, includes a cleaning chamber 1, and a fan filter unit a communicated with the cleaning chamber 1, wherein the gas is filtered by the fan filter unit a to be a clean gas, and the clean gas is introduced into the cleaning chamber 1, so that the cleaning chamber 1 is in a positive pressure state. The cleanliness class of the cleaning gas and the content of fine particles therein satisfy the contamination control requirements of the semiconductor device product class. Can realize keeping the cleanliness factor grade in the plasma process cavity to wasing microenvironment control in the cavity 1 through fan filter unit A, can avoid the pollutant to enter into wash in the cavity 1, reach and avoid wasing a plasma cleaning back secondary pollution, improve plasma cleaning process effect.

In this embodiment, the fan filter unit a includes a housing 6 mainly used for supporting each component, and an air inlet 7 and an air outlet 12 disposed at two sides of the housing 6, wherein a pre-filter is disposed at the air inlet 7, the ultra-high efficiency filter 8 is disposed at the air outlet 12, and a fan 9 is disposed between the pre-filter and the ultra-high efficiency filter 8. The pre-filter is mainly used for performing a coarse filtering effect on the air inlet 7 so as to prevent large-particle impurities from entering the chamber to cause potential damage to the fan 9 and the ultra-high efficiency filter 8; the blower 9 is mainly used for introducing airflow and conveying, the rotating speed of the blower 9 can be controlled by the controller, in order to prevent the blower 9 from directly blowing the ultra-high efficiency filter 8 and causing damage to the ultra-high efficiency filter 8, the common blower 9 is a centrifugal blower, the centrifugal blower can blow the airflow out along the circumferential direction, and thus the airflow in the chamber can be more smoothly and uniformly blown onto the ultra-high efficiency filter 8; the ultra-high efficiency filter 8 is mainly used for filtering tiny particles, the filtering effect of the ultra-high efficiency filter 8 on tiny particles is generally completed by two modes, namely filtering effect and adsorption effect, the filtering effect on particles with larger particle size is generally completed by physical filtering effect, the filtering effect on particles with smaller particle size is generally completed by electrostatic adsorption effect, and the filtering effect of the ultra-high efficiency filter 8 on tiny particles with the diameter of 0.1 μm can reach 99.99995%.

In this embodiment, two electrode plates and a support bracket 5 are arranged in the cleaning chamber 1, and projections of the electrode plates and the support bracket 5 on the air source device are located in an air outlet 12 of the air source device. The supporting bracket 5 is vertically arranged and positioned between the two electrode plates, and the air source device is arranged on the upper side of the cleaning chamber 1. The two electrode plates are respectively a left electrode plate 3 positioned on the left side of the supporting bracket 5 and a right electrode plate 4 positioned on the right side of the supporting bracket 5.

In this embodiment, the cleaning chamber includes a process gas inlet 10 and a process gas outlet 11 disposed on a sidewall of the cleaning chamber 1, the process gas inlet 10 is located on a side of a back surface of the support frame 5 where the cleaning member is disposed, and the process gas outlet 11 is located between a side of the support frame 5 where the cleaning member is disposed and the right electrode plate 4. And the air outlet 12 and the process gas outlet 11 are respectively located at two sides of the cleaning chamber 1.

In this embodiment, the fan filter assembly a generally works in the cleaning chamber 1 in a non-plasma state, and at this time, the cleaning chamber 1 is in a non-cleaning state, but a good cleaning state still needs to be maintained. That is, in other periods of plasma cleaning (for example, during the operation of taking and placing the cleaning piece), especially after the chamber door of the cleaning chamber 1 is opened, the cleaning piece is in an exposed state, and when the cleaning chamber 1 is in a positive pressure state, the contaminants outside the cleaning chamber 1 can be prevented from entering the inside of the cleaning chamber 1. Of course, the dirty particles in the cleaning chamber 1 may be filtered and purged in advance before the plasma cleaning process is started.

In the plasma cleaning process, after a cleaning piece is placed on a supporting bracket 5, high-frequency voltage can be generated through a plasma generating device 13, two poles of the high-frequency voltage are respectively connected to a left electrode plate 3 and a right electrode plate 4, so that a certain potential difference is formed between the left electrode plate 3 and the right electrode plate 4, meanwhile, the left electrode plate 3 and the right electrode plate 4 are in an insulating state, at the same time, a cleaning chamber 1 is vacuumized through a process gas outlet 11, cleaning process gas (such as helium, oxygen or other gases containing halogen elements and the like) is introduced into the cleaning chamber 1 through a process gas inlet 10 after a certain vacuum degree (such as 100pa) is reached, the process gas is ionized under high pressure after the high-frequency voltage reaches a certain value, namely, the process gas exists in a plasma state, namely, a plasma state 2 in which positive and negative charges exist simultaneously is formed between the left electrode plate 3 and the right electrode plate 4, because positive and negative charges are equal in quantity, the whole cleaning cavity 1 is neutral in charge, and in order to enhance the cleaning effect and avoid damage to a cleaning part, the support is generally made of an insulating material or subjected to insulating treatment.

As a changeable implementation mode, the plasma cleaning device comprises a cleaning chamber 1 and an air source device which is communicated with the cleaning chamber 1 and is provided with an air storage cavity, wherein the air source device leads clean air in the air storage cavity into the cleaning chamber 1, so that the cleaning chamber 1 is in a positive pressure state.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A plasma cleaning device is characterized by comprising a cleaning chamber (1), wherein the side wall of the cleaning chamber (1) is provided with a process gas inlet (10) and a process gas outlet (11); the cleaning device is characterized by also comprising an air source device communicated with the cleaning chamber (1), wherein the air source device is used for introducing clean air into the cleaning chamber (1) to enable the cleaning chamber (1) to be in a positive pressure state;

two electrode plates and a supporting bracket (5) are arranged in the cleaning cavity (1), the supporting bracket (5) is vertically arranged, the two electrode plates are respectively arranged at two sides of the supporting bracket (5), and the projections of the electrode plates and the supporting bracket (5) on the air source device are positioned in an air outlet (12) of the air source device;

the gas source device is arranged on the upper side of the cleaning chamber (1), and the process gas outlet (11) is positioned on the lower side of the cleaning chamber (1) opposite to the air outlet (12) of the gas source device.

2. The plasma cleaning apparatus according to claim 1, wherein the gas source device is a fan filter unit a having an ultra high efficiency filter (8).

3. The plasma cleaning device according to claim 2, wherein the fan filter unit A comprises a housing (6), an air inlet (7) and an air outlet (12) arranged on two sides of the housing (6), a pre-filter arranged at the air inlet (7), the ultra-high efficiency filter (8) arranged at the air outlet (12), and a fan (9) arranged between the pre-filter and the ultra-high efficiency filter (8).

4. Plasma cleaning device according to claim 3, characterized in that the fan (9) is a centrifugal fan.

5. The plasma cleaning apparatus according to claim 1, wherein the process gas inlet (10) is located on a side of the support frame (5) on which a cleaning member is provided.

6. The plasma cleaning apparatus according to claim 5, wherein the process gas outlet (11) is located between a face of the support frame (5) where the cleaning member is provided and one of the electrode plates.