CN100498420C - Fragment isolator for plasma light source of extreme ultraviolet laser - Google Patents

Abstract

A fragment isolator of extremely ultraviolet laser plasma light source is cylindrical rotary wheel being able to rotate in high speed. It is featured as arranging uniform rectangular channel at side surface and through center of said cylindrical body, setting cylindrical rotary wheel between target and optical system and making the three be on the same central horizontal line, setting rotation axle of said wheel to vertical direction being vertically crossed with said horizontal line, selecting initial operation state of said isolator to be at included angle Qa of channel central axle to central horizontal line.

Description

Fragment isolator for plasma light source of extreme ultraviolet laser

Technical field

The present invention relates to the fragment isolator of laser plasma light source, particularly fragment isolator for plasma light source of extreme ultraviolet laser.

Background technology

Usually extreme ultraviolet (EUV) optical wavelength according to the relation of Rayleigh diffraction limit and wavelength and digital aperture (NA), is used short wavelength's light source in 5nm-15nm scope, can improve big NA optical system limiting resolution greatly.The research and development of many applications such as high resolving power EUV living body biological microscope, high resolving power EUV photoetching and detection system in recent years, urgent need satisfies the EUV light source of performance requirement.But laser plasma light source produces the EUV light time to be faced laser (YAG laser) bombardment target and produces the fragment pollution problem, causes optical system to be polluted, and makes that system performance is serious to descend even can not work, and influences the serviceable life of optical system.

At present, part Study person is in order to solve the fragment pollution problem, at oneself system design different isolators, for example:

Document 1:T.Hatano et al.,＜Deposition Shutter Control for Figured MultulayerFabrication 〉, Precision Science and Technology for perfect surfaces, Y.Furukawa, Y.Mcri ﹠amp; T.Kataoka (Eds), The Japan Society for Precision Engineering, Tokyo, 1999, pp 292-297;

Document 2:M.Yamamoto et al.,＜Present Status of EUV Interferemeter Developmentat the Research Center for Soft X-ray Microscopy 〉, Optical and PrecisionEngineering, Vol.9, No.5,2001;

Document 3:M.Yamamoto et al.＜Compact debris shutter design of a laser-indeucedplasma source for high NA application 〉, SPIE proceedings, 2000, vol.4146, pp128-131;

Above-mentioned research all is before the substrate of deposition EUV multi-layer mirror, isolates fragment by three hole paths of hollow cylinder, and purpose is in the limit laser coating system, arrives the fragment of multi-layer mirror.Its design feature is as shown in Figure 2: pole section diameter 20cm, and sidewall three hole H1 diameter 7mm, H2 diameter 10cm, H3 diameter 10cm, hole H1 is near light source and target body, and hole H3 is near optical system.Since three holes, two passage asymmetric distribution, the isolation of wayward fragment, and simultaneously, the original state of isolator does not consider that passage is in suitable fleet angle in advance, just has fragment to pass through at the system works initial stage.The isolator of document 2,3 reports can be isolated the fragment of high-speed motion well, but the fragment of low-speed motion still can pass isolator, causes reflectance coating to deposit the pollution of inhomogeneous and vacuum system.

Summary of the invention

For overcoming the relatively poor defective of above-mentioned prior art low speed debris exclusion effect, the present invention proposes a kind of fragment isolator more pervasive, that be used for extreme ultraviolet (EUV) laser plasma light source.Spacer structures of the present invention is simple, be easy to control, can solve the EUV laser plasma light source and produce of the pollution problem of inevitable fragment when shooting at the target body swashing optical system, to the application of EUV laser plasma light source in the preparation of high precision zero defect multilayer film, EUV living body biological microscope, EUV high precision interferometry and EUV photoetching, have very important significance.

The present invention is by the following technical solutions:

According to light source and optical system correlation parameter and the kinematical theory of being set up, isolator of the present invention is a right cylinder high speed runner, the right cylinder side of isolator has a uniform cross section rectangular channel that runs through the right cylinder center, and the central axis of rectangular channel is by cylindrical center.The rotating shaft of right cylinder runner is cylindrical central shaft, and right cylinder runner isolator is installed between target and the optical system, and three's center is on the same horizontal line.The rotating shaft of right cylinder runner is a vertical direction, and intersects vertically with described horizontal line.

Cylindrical radius is R, highly is D, and passage is of a size of d in the circular arc chord length of cylindrical sidewall opening ₁, channel height is d ₂, rotating speed is ω, and isolator is L to the distance of target, and optical system is LL to the distance of target.The original state of isolator work is chosen in isolator and has certain initial fleet angle, and promptly the angle of channel center's axis and central horizontal line equals θ _AThe position, when the laser bombardment target produced plasma, isolator had initial fleet angle θ _AState under, rotate with angular velocity omega.The center subtended angle of access portal is 2 θ _W

Isolator of the present invention should satisfy following condition:

At first:

d ₁＝2Rθ _W，d ₂＝d ₁

d ₁When depending on light source characteristic and slap shot target body, to the requirement of beam divergence angle and optical system by light-struck size requirements: if the angle of divergence of light source is θ ₀Angle, the distance of light source irradiation optical system are LL, and so, the beam spot diameter, of light source irradiation optical system is:

z＝(LL)θ ₀，

Isolator passage of the present invention is at the arc size d of cylindrical sidewall opening ₁, channel height d ₂, cylinder height D should satisfy:

D>d ₁＝d ₂>z

So that make beam spot diameter, that light emitted goes out less than d ₁, d ₂Light can pass through isolator, do not restraint the interception of spot and the loss of energy.

The ultimate range that the segregate fragment of the present invention can move:

Y＝L+2R

Isolator rotating speed of the present invention:

ω＝2πv(rad/s)

V is a unit interval isolator rotation revolution (rps)

If:

θ ₁＝θ _A+θ _W θ ₂＝θ _A-θ _W

θ _A≥θ _W

When isolator of the present invention equals θ at the angle of described channel center axis and right cylinder runner, target and optical system three's central horizontal line _AThe time, be in original state, at this moment, access portal is in the fragment motion through outside the zone, and fragment is in by isolation.When isolator begins the high speed rotating with ω, the target of laser plasma bombardment simultaneously.Clock when isolator begins to rotate, passage rotates through θ ₂During angle, through regular hour T1 (that is: Δ T1, also represent the time of pathway closure state continuance for the first time) after, passage front opening position rotates to the zone of fragment motion process, that is: passage begins to open, after time, passage is opened end and is begun to close through Δ t1, and the moment that passage is opened end is t1.Rotation along with isolator, in the isolator rotary course, the time that experience was closed and opened to passage for the first time is T1 and t1, passage is in that to close for the first time the time that continues with open mode be Δ T1 and Δ t1, the process that passage so opens and closes can occur the 2nd in the process of isolator rotation, 3 ... n time.N is a laser pulse in the cycle, the switch periods of isolator switch passage, and the characteristic of its size and laser instrument and the speed of rotation of isolator are relevant, and the 2nd ... when each laser pulse of m arrives, repeat said process.For the ease of understanding, table 1 has been enumerated above-mentioned several states of n=5, and the time of corresponding state end experience and the time interval of this state continuance are as shown in table 1.

Table 1, isolator passage are opened with the shut-in time and are opened the time that continues with closed condition

1st closes

1st opens

2st closes

2st opens

3st closes

3st opens

4st closes

4st opens

5st closes

The state concluding time (S)	T1	t1	T2	t2	T3	t3	T4	t4	T5
											θ 2/ω	θ 1/ω	(π+θ 2)/ω	(π+θ 1)/ω	(2π+θ 2)/ω	(2π+θ 1)/ω	(3π+θ 2)/ω	(3π+θ 1)/ω	(4π+θ 2)/ω
State duration (S)	ΔT 1	Δt 1	ΔT 2	Δt 2	ΔT 3	Δt 3	ΔT 4	Δt 4	ΔT 5
											θ 2/ω	2θ W/ω	(π-2θ W)/ω	2θ W/ω	(π-2θ W)/ω	2θ W/ω	(π-2θ W)/ω	2θ W/ω	(π-2θ W)/ω

It should be noted that: when passage front opening process fragment flight range, with the sudden fragment admission passage of given pace, but, because isolator and passage are always at high speed rotating, the fragment that satisfies the given pace distribution still can be blocked by the sidewall of passage and isolate, and the fragment of admission passage can all not pass through.

The present invention is isolated and the rate distribution of the fragment that passes through is analyzed as follows:

If fragment arrives the distance that isolator passes through: Y=L+2R by the target outgoing, according to shown in the table 1, at pathway closure each time with in opening, fragment is by being expressed as with segregate critical speed V:

Δ T ₁=t ₁-0 (closing for the first time)

Y/ (T ₁+ Δ t ₁)=Y ω/θ ₁＜V＜Y/T ₁=Y ω/θ ₂(by)

V〉Y/T ₁=Y ω/θ ₂(isolation)

Following formula represents, when closing for the first time, and critical speed Y/ (T ₁+ Δ t ₁)=Y ω/θ ₁＜V＜Y/T ₁=Y ω/θ ₂Fragment can pass through critical speed V Y/T ₁=Y ω/θ ₂Fragment isolated.

Δ t ₁=t ₁-T ₁(1st is open-minded)

V〉Y/t ₁=Y ω/(θ ₁) (by)

V＜Y/t ₁=Y ω/(θ ₁) (isolation)

That is: when opening for the first time, critical speed Y ω/θ ₁The fragment of＜V can pass through, critical speed V＜Y/T ₁=Y ω/θ ₁Fragment isolated.

Δ T ₂=T ₂-t ₂(2st closes)

Y/t ₂＜V＜Y/T ₂=Y ω/(π+θ ₂) (by)

V〉Y/T ₂=Y ω/(π+θ ₂) (isolation)

That is: when closing for the second time, critical speed Y/t ₂＜V＜Y/T ₂=Y ω/(π+θ ₂) fragment can pass through critical speed V Y/T ₂=Y ω/(π+θ ₂) fragment isolated.

Δ t ₂=t ₂-T ₂(2st is open-minded)

V〉Y/t ₂=Y ω/(π+θ ₁) (by)

V＜Y/t ₂=Y ω/(π+θ ₁) (isolation)

That is: when opening for the second time, critical speed V〉Y/t ₂=Y ω/(π+θ ₁) fragment can pass through critical speed V＜Y/t ₂=Y ω/(π+θ ₁) fragment isolated.

Δ T ₃=T ₃-t ₂(3st closes)

V＜Y/T ₃=Y ω/(2 π+θ ₂) (by)

V〉Y/T ₃=Y ω/(2 π+θ ₂) (isolation)

That is: when closing for the third time, critical speed V＜Y/T ₃=Y ω/(2 π+θ ₂) fragment can pass through critical speed V Y/T ₃=Y ω/(2 π+θ ₂) fragment isolated.

Δ t ₃=t ₃-T ₃(3st is open-minded)

V〉Y/t ₃=Y ω/(2 π+θ ₁) (by)

V＜Y/t ₃=Y ω/(2 π+θ ₁) (isolation)

That is: when opening for the third time, critical speed V〉Y/t ₃=Y ω/(2 π+θ ₁) fragment can pass through critical speed V＜Y/t ₃=Y ω/(2 π+θ ₁) fragment isolated.

Δ T ₄=T ₄-t ₃(3st closes)

V＜Y/T ₄=Y ω/(3 π+θ ₂) (by)

V〉Y/T ₄=Y ω/(3 π+θ ₂) (closing)

That is: when closing for the 4th time, critical speed V＜Y/T ₄=Y ω/(3 π+θ ₂) fragment can pass through critical speed V Y/T ₄=Y ω/(3 π+θ ₂) fragment isolated.

Δ t ₄=t ₄-T ₄(4st is open-minded)

V〉Y/t ₄=Y ω/(3 π+θ ₁) (by)

V＜Y/t ₄=Y ω/(3 π+θ ₁) (isolation)

That is: when opening for the 4th time, critical speed V〉Y/t ₄=Y ω/(3 π+θ ₁) fragment can pass through critical speed V＜Y/t ₄=Y ω/(3 π+θ ₁) fragment isolated.

And the like:

The n subchannel is opened the time of end: ((n-1) π+θ ₁)/ω, n=1,2,3....

The n subchannel is closed the time of end: ((n-1) π+θ ₂)/ω, n=1,2,3....

The n subchannel is opened the critical speed of the segregate fragment of end energy:

$V_{\mathrm{SCn}}=\frac{(L+2R)\mathrm{\ω}}{(n-1)\mathrm{\π}+{\mathrm{\θ}}_1},n=\mathrm{1,2,3}....$

The n subchannel is closed the critical speed that end can be passed through the fragment of isolator:

$V_{\mathrm{pCn}}=\frac{(L+2R)\mathrm{\ω}}{(n-1)\mathrm{\π}+{\mathrm{\θ}}_2},n=\mathrm{1,2,3}....$

Therefore, the fragment that in the cycle of channel switch each time, some is arranged all, has a certain speed passes through, and the fragment that also have some, has a certain speed is isolated.

When the fragment critical speed satisfied following relationship, fragment was isolated, and can not arrive optical system:

${\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="C200510086792E00123.png,C200510086792E00151.png"\; state="\{\{state\}\}">V</figure-callout>}}_1=\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_1}>V_S$ With $V_S>\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_2}={\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="C200510086792E00123.png,C200510086792E00152.png"\; state="\{\{state\}\}">V</figure-callout>}}_2$

And the fragment that speed Vp is distributed in the following scope will be by the passage of isolator:

${\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="C200510086792E00123.png,C200510086792E00151.png"\; state="\{\{state\}\}">V</figure-callout>}}_1=\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_1}<V_P<\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_2}={\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="C200510086792E00123.png,C200510086792E00152.png"\; state="\{\{state\}\}">V</figure-callout>}}_2$

Wherein, V ₁And V ₂Two critical speeds of expression fragment.

In sum, needs according to practical application, relation between the size of optimal design isolator, position and rotating speed and the laser plasma pulsed frequency, the present invention just can isolate fragment to greatest extent, that is: the fragment speed coverage maximum of being isolated by isolator of the present invention, thereby reach the purpose of prevention fragment pollution, do not influence light simultaneously and pass through.

When the laser bombardment target produced plasma, isolator had initial fleet angle θ _AState under, with ω angular velocity rotation, stop the work of fragment isolator after laser instrument quits work again.

Description of drawings

Further specify the present invention below in conjunction with the drawings and specific embodiments.

Fig. 1 a is the stereographic map of isolator of the present invention; Fig. 1 b is the front view of isolator of the present invention; Fig. 1 c is the A-A face cut-open view of isolator of the present invention; Among the figure: 1 isolator, 2 passages, 3 targets, 4 optical systems;

Fig. 2 is the isolator synoptic diagram that document 3 uses;

Fig. 3 a is isolator original state (t=0) synoptic diagram, and Fig. 3 b is t=T1+ (1/2) Δ t ₁The synoptic diagram of state;

Fig. 4 constantly opens and closes and 4 cycle synoptic diagram for the isolator passage;

Fig. 5 is the structure and the position view of embodiment isolator;

Fig. 6 is segregate fragment critical speed V ₁And V ₂Distribution with the switch periods n of isolator passage.

Embodiment

As shown in Figure 1, isolator of the present invention is the right cylinder runner 1 of a high speed rotating.The side of right cylinder runner 1 has a uniform cross section rectangular channel 2 that runs through the right cylinder center, the central axis of rectangular channel 2 is by the center of right cylinder 1, the rotating shaft of right cylinder runner 1 is cylindrical circular central axle, target 3 and optical system 4 are installed in the two ends of above-mentioned right cylinder runner 1 respectively, and three's center is on the same horizontal line.The rotating shaft of right cylinder runner is a vertical direction, and intersects vertically with described horizontal line.

Described passage 2 is d at the arc size of right cylinder runner 1 sidewall opening ₁, described passage 2 highly is d ₂, the circular section radius of right cylinder runner 1 is R, highly is D, and rotating speed is ω, and isolator is L to the distance of target 3, and optical system 4 is LL to the distance of target.The original state of isolator work is chosen in described passage 2 central axis and horizontal angle equals θ _AThe position, the center subtended angle of the hollow opening of passage is 2 θ _W

The principle of work of the present invention and the course of work are as follows:

When isolator of the present invention equals θ at described passage 2 central axis and horizontal angle _AThe time, be in original state, this moment t=0, shown in Fig. 3 a.At this moment, the opening of described passage 2 is in the fragment motion through outside the zone, and fragment is isolated.When isolator begins the high speed rotating with ω, the target of laser plasma bombardment simultaneously.When beginning to rotate, isolator clocks, behind regular hour T1 (Δ T1), that is: when described passage 2 rotated through θ 2 angles, described passage 2 front opening positions rotated to the zone of fragment motion process, that is: passage begins to open, shown in (a) state of Fig. 4.When isolator turns over θ ₁=θ _A+ θ _WAfter, passage is in a certain state of opening stage, shown in Fig. 3 b.After the Δ t1 time, passage is opened end and is begun to close, and the moment that passage is opened end is t1, shown in (b) state of Fig. 4.Rotation along with isolator, in the isolator rotary course, the time that experience was closed and opened to passage for the first time is T1 and t1, it is Δ T1 and Δ t1 that passage is closed the time that continues with open mode for the first time, the process that passage opens and closes like this can occur the 2nd in the process of isolator rotation, 3,4 (as (c) of Fig. 4, (d), (e), (f), (g) shown in the state) ... n time, n is that a laser pulse is in the cycle, the switch periods of isolator switch passage, the characteristic of its size and laser instrument and the speed of rotation of isolator are relevant, and the 2nd ... when each laser pulse of m arrives, repeat said process.As the YAG laser pulse frequency is 10Hz, and the time of a laser pulse is 0.1s.Change 0.1 isolator changes 50 in second, revolution passage 2 switches open and cut out 2 times, that is: a laser pulse is in the time, and isolator passage 2 is opened and closed 100 times.When ensuing laser pulse constantly arrived, isolator continued to rotate, constantly repeat said process.

The present invention's one specific embodiment as shown in Figure 5, the isolator per second changes 500 and changes.

ω＝2πv(rad/s) θ _W＝d ₁/2R

v＝500(rps)

d ₁＝8.736mm，L＝320mm，R＝30mm，θ _W＝0.146rad，θ _A＝2θ _W＝0.292rad

The angle of divergence of laser instrument:

θ ₀＝0.00273(rad)

Target 3 arrives the distance of optical system 4:

LL＝1100mm

Laser arrives the beam spot diameter, of optical system:

Z＝3mm(Z<d1)

Listed according to following formula result calculated such as table 2, the result shows: speed V _sLess than V ₁Or greater than V ₂Fragment isolated by isolator of the present invention.

${\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="C200510086792E00123.png,C200510086792E00151.png"\; state="\{\{state\}\}">V</figure-callout>}}_1=\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_1}>V_S$ Or $V_S>\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_2}={\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="C200510086792E00123.png,C200510086792E00152.png"\; state="\{\{state\}\}">V</figure-callout>}}_2$

Fig. 6 is segregate fragment critical speed V ₁And V ₂Distribution with the switch periods n of isolator passage.As shown in Figure 6, isolator of the present invention can be realized the fragment of rate distribution in a big way isolated, and segregate fragment rate distribution is V in the drawings ₂The top of curve and V ₁The bottom of curve, and the fragment by isolator is only at V ₁And V ₂In the very zonule that curve surrounds.Can see that the rate distribution scope of being isolated fragment is bigger, illustrate that the present invention has bigger speed coverage rate.Simultaneously, isolator of the present invention both can have been isolated the bigger fragment of movement rate, also can isolate the less fragment of movement rate.As the YAG laser pulse frequency is 10Hz, and the time of a laser pulse is 0.1s.In 0.1 second, isolator changes 50 and changes, and each commentaries on classics channel switch is opened and closed 2 times, that is: a laser pulse is in the time, and the isolator passage is opened and closed 100 times.During n=1, isolate high speed V＜2724.01m/s, and V〉fragment of 8260.87m/s, at this moment, the fragment that speed is low does not also fly to the position of isolator, treat that next rotation period arrives, have part to be isolated, part is passed the isolator passage, and during n=100, isolate V＜3.833m/sV〉the extremely low fragment of 3.837m/s speed in the very little scope of rate distribution, can pass through isolator.

In the different application occasion of reality, can be according to laser pulse, optical system and the relative position of different application systems, the size of design isolated device (R, d), initial fleet angle θ _A, subtended angle 2 θ _W, rotating speed etc.

Table 2, segregate fragment critical speed V1 and V2 are with the distributed data of the switch periods n of isolator passage

n	v2(m/s)	v1(m/s)	n	v2(m/s)	v1(m/s)
1	2724.014	8260.87	19	20.94876	21.0573
						2	333.4796	363.2887	20	19.85423	19.9517
3	177.6116	185.7283	21	18.86839	18.9564
						4	121.0384	124.7538	22	17.97583	18.05569
5	91.79853	93.91992	23	17.16389	17.23669
						6	73.93715	75.30717	24	16.42214	16.48876
7	61.89429	62.85147	25	15.74183	15.80304
						8	53.22502	53.93131	26	15.11565	15.17208
9	46.68591	47.22844	27	14.53739	14.58957
						10	41.57777	42.00752	28	14.00173	14.05014
11	37.47719	37.826	29	13.50415	13.54917
						12	34.11284	3440159	30	13.04072	13.0827
13	31.30277	31.54574	31	12.60804	12.64727
						14	28.92043	29.1277	32	12.20315	12.2399
15	26.87507	27.05397	33	11.82346	11.85795
						16	25.0999	25.25588	34	11.46668	11.49912
17	23.54472	23.68191	....	.............	.............
						18	22.17101	22.29262	100	3.832983	3.836601

Claims (3)

1, a kind of fragment isolator for plasma light source of extreme ultraviolet laser, it is characterized in that it is the right cylinder runner [1] of a high speed rotating, the side of right cylinder runner [1] has a uniform cross section rectangular channel [2] that runs through the right cylinder center, the central axis of rectangular channel [2] is by cylindrical center, the long limit of rectangular channel [2] is parallel with cylindrical end face, and the rotating shaft of right cylinder runner [1] is cylindrical central shaft; Right cylinder runner [1] is installed between target [3] and the optical system [4], and three's center is on the same horizontal line; The rotating shaft of right cylinder runner [1] is a vertical direction, and intersects vertically with described horizontal line; Described passage [2] is of a size of d in the chord length of the circular arc of right cylinder runner [1] sidewall opening ₁, described passage [2] highly is d ₂, right cylinder runner [1] highly is D, the beam spot diameter, of light source irradiation optical system is z:

D>d ₁＝d ₂>z。

2, according to the described fragment isolator for plasma light source of extreme ultraviolet laser of claim 1, it is characterized in that:

(1) speed V _sThe fragment that drops in the following scope is isolated by isolator:

$V_1=\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_1}>V_S$ Or $V_S>\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_2}=V_2,$

(2) fragment that is distributed in the following scope of speed Vp will be by the described passage [2] of isolator:

$V_1=\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_1}<V_P<\frac{(L+2R)\mathrm{\&omega;}}{(n-1)\mathrm{\&pi;}+{\mathrm{\&theta;}}_2}=V_2,$

Wherein:

θ ₁＝θ _A+θ _W，θ ₂＝θ _A-θ _w，θ _A≥θ _W，

In the formula: V1, V2: two critical speeds of motion fragment, R: the circular section radius of right cylinder runner [1], ω: right cylinder runner [1] rotating speed, L: isolator is to the distance of target [3], θ _A: the initial fleet angle of isolator, the described horizontal angle at promptly described passage [2] central axis and right cylinder runner [1], target [3] and optical system [4] three center, 2 θ _W: the center subtended angle of described access portal, d ₁=2R θ _W

3, according to the described fragment isolator for plasma light source of extreme ultraviolet laser of claim 2, it is characterized in that: it is θ that the original state of isolator work is chosen in initial fleet angle _AThe position; When laser bombardment target [3] produced plasma, isolator had initial fleet angle θ _AState under, with angular velocity omega rotation, stop the work of isolator after laser instrument quits work again.

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