Extreme ultraviolet photolithographic (EUVL) be at present the most most potential, the node IC volume productions such as CD32/22/16nm can be met
Photoetching technique.Owing to major part gas all absorbs the extreme ultraviolet of 13.5nm, especially Hydrocarbon, water vapour etc. are to pole
Ultraviolet light has strong Absorption, it is therefore desirable to be supplied to the vacuum environment of litho machine cleaning.
Having substantial amounts of electronic circuit system inside litho machine, pcb board therein and electronic devices and components are under vacuum conditions
Substantial amounts of pollution gas and microgranule, heavy damage litho machine working environment, it is therefore desirable to for electronic circuit system can be discharged
Design vacuum seal casinghousing, to prevent its pollution gas discharged and microgranule to be directly entered litho machine internal work environment.
For extreme ultraviolet etching system, the most important performance indications of vacuum seal casinghousing are not integral leakages, but hydrocarbonization
The dividing potential drop leak rate of the gas such as compound, water vapour.
Application for a patent for invention CN103335795A proposes a kind of vacuum seal dividing potential drop leak rate based on dynamic flow method and surveys
Amount system, as it is shown in figure 1, it discloses a kind of vacuum seal dividing potential drop leakage rate measurement system and measuring method, this measurement system
System includes that supervacuum chamber (202), test cabinet (206), sample room (207), supervacuum chamber (202) lead to test cabinet (206)
Small holes (204) is connected, and test cabinet (206) is connected with sample room (207) by gas pipeline (214).First air pump
Group (201) extracts gas from this supervacuum chamber (202)；Sample room (207) is used for placing vacuum seal (208).First
The gas componant in this supervacuum chamber (202) and test cabinet (206) measured by mass spectrograph (203) and the second mass spectrograph (205)
Dividing potential drop.This application for a patent for invention measures vacuum seal in inflation and vacuum two by two mass spectrographs under system balancing state
For the dividing potential drop of specific gas component under the state of kind, directly it is calculated this vacuum seal and the dividing potential drop of this gas component is leaked
Rate.This device uses mass spectrograph to measure the partial pressure of aperture both sides, calculates orifice conductance for concrete gas component, records vacuum
The dividing potential drop leak rate of sealing member and integral leakage.In order to more accurately, comprehensively measure and evaluate the gas leakage performance of vacuum seal, need
Solve following problem: (1) eliminates as much as vacuum gauge x-ray effect, Electron Excitation desorption effect and chemical effect etc.
Impact on test process；(2) vacuum seal gas leakage component and dividing potential drop leak rate thereof dynamically, in real time, are accurately measured；(3) dynamically,
In real time, the integral leakage of vacuum seal is accurately measured.
Summary of the invention
The present invention is a kind of sealing member dividing potential drop leakage rate measurement device and method.Vacuum chamber and vacuum pump group are by current limliting aperture
It is connected, with referance leak for comparing foundation, is calculated as measuring instrument with mass spectrum, measure vacuum seal by dynamic comparison and divide
Pressure leak rate.
The invention provides a kind of dividing potential drop leakage rate measurement device, for measuring vacuum seal gas leakage component and each component
Dividing potential drop leak rate, this device includes the first vacuum gauge (1), mass spectrograph (2), referance leak (3), stop valve (4), vacuum chamber (5), inserts
Plate valve (6), angle valve (7), current limliting aperture (8), air pump group (9), the second vacuum gauge (10), electromagnetic valve (11), air pump group
(12), stop valve (13), gas cylinder (14) and vacuum seal (15), wherein, the first vacuum gauge (1) and mass spectrograph (2) are respectively
Being joined directly together with vacuum chamber (5), referance leak (3) is connected with vacuum chamber (5) by stop valve (4), and air pump group (9) is by inserting
Plate valve (6) or be connected with vacuum chamber (5) by angle valve (7), current limliting aperture (8), placement vacuum seal in vacuum chamber (5)
(15), vacuum seal (15) is connected with air pump group (12) by electromagnetic valve (11), by stop valve (13) and gas cylinder (14)
Connecting, the second vacuum gauge (10) is connected on the loading line of vacuum seal (15).
Additionally, present invention also offers a kind of dividing potential drop leakage rate measurement method, be used for measuring vacuum seal gas leakage component and
The dividing potential drop leak rate of each component, described method of testing comprises the following steps: (1) measures helium background ions stream I0With background gas group
Divide dividing potential drop PI, bg；(2) measurement standard small opening helium ion stream Is；(3) vacuum seal helium ion stream I is measuredLWith gas leakage component
Dividing potential drop PI, L；(4) vacuum seal dividing potential drop leak rate Q is calculatedI, LWith integral leakage QL。
It is an advantage of the current invention that: with referance leak for comparison foundation, improve leakage rate measurement precision, maximum possible eliminates
The desorption impact on test process such as effect and chemical effect of vacuum gauge x-ray effect, Electron Excitation, dynamically, in real time, accurately
Measure vacuum seal gas leakage component and dividing potential drop leak rate thereof and integral leakage, seal such that it is able to accurately, comprehensively evaluate vacuum
The gas leakage performance of part.
Detailed description of the invention
It is more fully described the illustrative embodiments of the disclosure below with reference to accompanying drawings.Although accompanying drawing shows these public affairs
The illustrative embodiments opened, it being understood, however, that may be realized in various forms the disclosure and the reality that should not illustrated here
The mode of executing is limited.On the contrary, it is provided that these embodiments are able to be best understood from the disclosure, and can be by these public affairs
What the scope opened was complete conveys to those skilled in the art.
According to the embodiment of the present invention, propose a kind of dividing potential drop leakage rate measurement device and the vacuum that uses this device to realize is close
Sealing dividing potential drop leakage rate measurement method.
As in figure 2 it is shown, vacuum seal dividing potential drop leakage rate measurement device mainly includes the first vacuum gauge 1, mass spectrograph 2, standard
Small opening 3, stop valve 4, vacuum chamber 5, push-pull valve 6, angle valve 7, current limliting aperture 8, air pump group the 9, second vacuum gauge 10, electromagnetic valve
11, air pump group 12, stop valve 13, gas cylinder 14 and vacuum seal 15.
First vacuum gauge 1 and mass spectrograph 2 are joined directly together with vacuum chamber 5.First vacuum gauge 1 is for monitoring the true of vacuum chamber 5
Reciprocal of duty cycle.First vacuum gauge 1 can be 1 gamut rule, it is also possible to be the combination of different range vacuum rule.Mass spectrograph 2 is used for surveying
Gas component and ion stream thereof or dividing potential drop in amount vacuum chamber 5.The vacuum only monitored when the first vacuum gauge 1 arrives a certain value
After, mass spectrograph 2 could be opened, in order to avoid burning mass spectrograph 2 or reducing the service life of mass spectrograph 2.
Referance leak 3 is connected with vacuum chamber 5 by stop valve 4.Referance leak 3 was calibrated for providing to vacuum chamber 5
Comparison air-flow.According to the different range of vacuum seal 15 leak rate, 1 referance leak or several different range mark can be set
The combination of quasi-small opening.
Air pump group 9 is connected by push-pull valve 6 or by angle valve 7, current limliting aperture 8 with vacuum chamber 5.The stream of push-pull valve 6
Lead relatively big, be mainly used in vacuum chamber 5 is taken out base vacuum.The conductance of current limliting aperture 8 is less, can improve and effectively measure signal, screen
Cover the pumping speed fluctuation of air pump group, be mainly used in the leakage rate measurement of vacuum seal.
Vacuum seal 15 is placed in vacuum chamber 5.Vacuum seal 15 by electromagnetic valve 11, stop valve 13 respectively with bleed
Pump group 12 and gas cylinder 14 connect, to realize inflation and two kinds of operating modes of evacuation of vacuum seal 15.Second vacuum gauge 10 connects
On the loading line of vacuum seal 15, in order to pressure in monitoring vacuum seal 15.
Vacuum chamber 5 uses rustless steel or aluminium alloy manufacture.Its sealing member uses metal material, to reduce the absorption to helium
And infiltration.Vacuum chamber 5 can also arrange heating system, to reduce system background, to improve the measuring precision.
Testing process and the computational methods of sealing member dividing potential drop leak rate are as follows:
(1) helium background ions stream I is measuredOWith background gas partial component pressure PI, bg
Vacuum seal 15 puts into vacuum chamber 5, starts air pump group 9, opens push-pull valve 6, closedown angle valve 7 to vacuum chamber
5 evacuation, start air pump group 12, open electromagnetic valve 11 vacuum seal 15 is carried out evacuation.After being evacuated to base vacuum, beat
Opened angle valve 7, closedown push-pull valve 6, by current limliting aperture 8 to vacuum chamber 5 evacuation.Use mass spectrograph 2 to monitor helium ion stream, treat
After helium ion stream is stable, read helium background ions stream IOWith background gas partial component pressure PI, bg。
(2) measurement standard small opening helium ion stream Is
Open stop valve 4, the helium of referance leak 3 is introduced vacuum chamber 5.Use mass spectrograph 2 to monitor helium ion stream, treat
After helium ion stream is stable, read referance leak helium ion stream Is。
(3) vacuum seal helium ion stream I is measuredLWith gas leakage partial component pressure PI, L
Close stop valve 4.Open stop valve 13, in vacuum seal 15, be filled with the helium of desirable pressure, close cut-off
Valve 13.Use mass spectrograph 2 to monitor helium ion stream, after helium ion stream is stable, read vacuum seal helium ion stream IL
With gas leakage partial component pressure PI, L。
(4) vacuum seal dividing potential drop leak rate Q is calculatedI, LWith integral leakage QL
Vacuum seal helium leak rate Q4, LFor:
In formula: QsFor the helium leak rate of referance leak, the gas component 4 representated by footmark 4 is helium.
The dividing potential drop leak rate Q of vacuum seal gas component iI, LFor:
In formula: MHeFor helium gas molecules amount；MiMolecular weight for gas component i.
Vacuum seal integral leakage QLFor:
In formula: n is that vacuum seal 15 is leaked gas constituent species number.
From above formula, for the steam that extreme ultraviolet etching system is paid close attention to and Hydrocarbon, its dividing potential drop
Calculation of leak rate formula is respectively as follows:
The gas group that wherein footmark 18 represents
Dividing 18 is H2O.
The above, the only present invention preferably detailed description of the invention, but protection scope of the present invention is not limited thereto,
Any those familiar with the art in the technical scope that the invention discloses, the change that can readily occur in or replacement,
All should contain within protection scope of the present invention.Therefore, protection scope of the present invention answers the described protection model with claim
Enclose and be as the criterion.