GB2213984A - A portable scanning electron microscope - Google Patents

Description

c, 1 z,Q n It 12 j d- 7 r, 7 T PORTA3-7-E SCIANNING ELEC7TRON MICRCSC".

"'he invention relates to a portable C 1 n 3 13-1 sca,nnnR electron microscone. T he number off scanning electron microscoues has recently increased. Por their bif of -focus t 1 bhey are 1Drelferably used.'-'o r c h e c k_ n.2 -- o d u c tl o n W - -orocesses and for surface deformatior st-u,-,-, -he effects of --'-'at4- ue.

especiall-11:7 when checking t The main drawback of prior art scanning e' on' ectron microscopes is that,y ob,-ec+l-- a -eA size can be che- -t' -ha- 7 im4 J1 - -ked therew- -, sc des'.-r-ac'bve methods of checking must be used, 1 4- because, the dimensions o Uhe sam-ple tc be checked may not exceed those of the opening in. -- zpecimen chamber, so that very often a deteriorating or irreparable destruction of a rart, from which said sample was taken is necesssry.

In order to eliminate this an electron microscope was designed, iGhe vacuum part of which was se-carated from the envronment a diaphragm of a very small diameter, 70, micrometres, said vacuum part being evacuated by a verv powerful pumping unit, which co-nt,4-.nuc,s!77 comuensates for leakage of th-is 'nduce vacuum - The main drawback of this solution is a very limited -field of vision due to the,,Lze of said d'-'a-ohrag-m, a vacuum hele.roRene4-t-, in an op-'L-- ca'- ax-s reRJon and a d"us4on c' e'ect-ons sca-"-+

1 -- - -- d b a c k b Y the object, which res,,i---:s in a T)oor auality of imaRe.

To avoid these shortcomings a -pcr',,a,-!-e electron scanning microscope was designed, the men chamber of which is i., il,: -o-IE srec s 1. tom -op-rt o-cer, and ada-oted for vaciium-tiaht sep-t-nR on a so!-4 2155 3 0 surface of ar object on investigated place. 7- a tJgated place +he co-!limn of better choice of Jnvest- u -L U - n_a elec±-- -- be emb-dded said scann.-n microsco-oe car n a specimen chamber throligh spherical sea-., in the column could be leaned, whi ' c.,., enables the of' ncidence o-" a central, electron beam to be changed.

Drawbacks of this tilting of a column results i -o distance ---'-ween + u t chanae c. he 11hat observed surface an-; final, lens of th-e s-Ts4-em L 4- J f 2 ,he Magr.._ LCation of th-e- Jim.age changes as well.

" --h4 Anot-her drawback o- 1 _s sollation is that the surroundings of 1. 1he observed spot must be a ulane, the size of which must be bigger than the size of the seal of the bottom of s-oecimen chamber of the - -L. U ss canning electron of m4croscone in cues'-4on.

"he above mentioned drawbacks of prior art s o lut. i oons ar =_ p -- a i c ally -- e mo v e cl by a pc c -- t ab scanning electron microscope according to this invention, the essence of which consists in tha-.!, it comprises a specimen chamber having a base in the middle of which is provided a sigh-tt o-oen-i.n-R, th-e size of which is bigger -uhan 'he maxi-mum ses-pot wolk-ble ir the plane of the sight opening, and is vacaum-t-',-Rh-'1-,!y and traversably seated on a base board, which is provided in its middle -cart with a hole cominun.4ca.',4ng with the sight oDening, the base lboard' being th a first seal, provided on its bottom s,-,-,-oace wit surround.Lng said hole. In one - cre'-erreo' embodiment said base board is --ov-ded with adjus'.ng screws - - U - -h motion and/or said specimen chamber is provided wit -her Drefer--ed embodiment is -or3v4 screws. Anot ded with a set of base boards, the size and shape of bottom surface and first seal of each base board w h i C"-o o i n -- solution are 'hat bigger n imaae distortion and v- 7 35) 1 - y p i c al e s z a t e,.

one d -!-'-'eren4.

being adapted t surf ace.

The advantages of zortable scanning electron microscoiDe accordinR to the or olserv4na include that seeking of a suitable suot - - - W in the m-'.-roscoDe does result neither i.n distortion, nor in a change of magnification of the image due to the tilting of an electron beam. Another advantage of this solution consist in that for different.

1 i nve s t i gaz e d su r f ac e s i ts J_ s e as i I,,r p os si - z t, provide exchangable base boar's wh se2--s, the and sh.ape c-' which are adanted to i. surrounding of an observed spolu.

The invention will now be described, in more detail, with the Inelp of the accompan, ying diagrammatic drawing, which illustrates a -preferred embodiment of a portable scanning elec-tron microscope according to the invention.

-i led a On the invest-gated surface 1 is sea+ 3, base board 2 provided with a -P-'rs'U vacuum sea,encompassing a hole 4 in said base board 2. On said base board 2 is situated a snecimen chamber, in the bottom of which is provided a sight opening 6. m-he specimen chamber 5 su-P-Dorts a column '7 and both communicate with a pumping unit, P. The base board 2 is provided with adjusting screws 9, while said s- pecimen chamber 5 is -)rov-ded with motion screws 10. A second vacuum seal 11 Is arranged between saspecimen chamber -7) and said base board 2. in use of the -Dortable scanning electron microscoDe according to the invention an o-cerator takes the microscope to an investigated surface 1 and -ed surface 1, puts its base board 2 on the investigat lace 1 is inside of the so that the investigated sur. hole 4 of the base board 2 and the --"'-rslu vacuum seal S - - AL - Cz 1 r_ -3 seats with its whole circumference on sa._:_ investigated sur--"a--e 1 around the investigated' spot.

-o e the miCrosco is evacaa-',,e.

n and stabiliZed, especially --':'or a greater res4-----.ane against vibrations, by tighten-ing screws 9, -oush. then ap-ainst said investigated surface microscope is then put', into operation, the electron beam scanning scross a small spot of invest-gated >ace i near the axis of an emect sur-IL Uron outica -he s- bh t system. The column 7 wit -ecimen chamber could ther. be, with the he'--. of,nc--:--on secrews 4 C Oicat d -preferably Jin a survey magni- ion mode, slidably 1 n moved over the investigated surface and a'--,er find L_ - the operator has been for of a suitable spot the investigation could begin.

The invention could -Preferably be used -for non-destructive surface analysiss of bigger surfaces, ects on a4----o-,Langn eg for investigating fatigue e-IL- U -s.

-!e parts and ot e part wings, missi her bigger machinj- b v a D um, r - n 2 u nJ_ 11 - - - v 1 1 _ c:;"' 7 CLATMS 1.

A portable scanning elect--,:n mic-r cs cope, com-crising a specimen chamber having.-:, base in 2.

n-n-z nz., m idd e of w h J1 ch 1; -- pro v ided a s s,-ze x 4 - of which is bigger than the 2 M11m spot w..bb--e t 1Ihe sight opening p'Lane, and is and uraversably sealed on a hase board, w'n-'ich is provid--- J_ t in i.s middle part with a hole. COMrjln4Ln-a'.,--.t--R Wi -- the sighl, opening, the base boar,- being further provided on its bottom surface wth 9. first seal, encomDass-n=-- S a i d,, 0 1 --.

A mortable scanning electron mi c--osco,.e -'s h e b

Claims (1)

1. according to Claim 1, wherein-. base bcard Js -orov.A---d with

   adiUS+.4L.-g screws.

   U A -portable scanning electron microsco-oe according to Claim 1 or 22, where-in the specimen -h motion screws.

   chamber is nrovided wit L.

   A portable scanning e'-ec-.--on m,-cr.--scorz- - 1 according to any one Of L9'-M ' tUC 79 - r e_. ' provde,' -,Tth a set of base boards, the size and shape of bc Uom surface and first seal of each base bca---' be-ing adapted to one different typical investigated- surface.

   A -portable scanning electron m-;---.osco-ce according to Claim 1, constructed an, adapted to operate substantially as here-in with reference to, and as shown the accom.panying d rawi-,, g.

   Published 1986 at The Patent, Office. State House. 5671 High Holborn, London WC1R 4TP- Purther copies mkv be obtained from The Patent office, Sales Branch, St Mary Cray. Orpington. Kent BRS 3RD Printed by Multiplex techniques ltd. St Vla:7 Cray. Kent. Con. 1 18-,.