Radiant energy – Inspection of solids or liquids by charged particles – Methods
Reexamination Certificate
2003-03-26
2004-08-24
Lee, John R. (Department: 2881)
Radiant energy
Inspection of solids or liquids by charged particles
Methods
C250S310000, C250S305000, C250S397000, C324S754120, C324S750010
Reexamination Certificate
active
06781123
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a charged particle beam control element for controlling a trajectory or a cross-sectional shape of a charged particle beam by an electrostatic field, a method of fabricating the charged particle beam control element, and a charged particle beam apparatus.
The conventionally well-known charged particle beam control elements for controlling the trajectory or the cross-sectional shape of the charged particle beam by the electrostatic field include electrostatic deflectors, electrostatic lenses, stigmators, and so on.
FIG. 11
is a top plan view to show a conventional electrostatic deflector
100
.
FIG. 12A
is a figure to show an A—A cross section of FIG.
11
and
FIG. 12B
a figure to show a B—B cross section of FIG.
11
.
The electrostatic deflector
100
has octupole metal electrodes
101
(see FIG.
11
). Each of the metal electrodes
101
is fixed to the inside of an insulating sheath
102
with fixing screws
103
,
104
(see FIG.
12
A). A voltage-applying wire
105
to each metal electrode
101
is directly fixed to the corresponding metal electrode
101
with a wiring screw
106
(see FIG.
12
B).
In this electrostatic deflector
100
, an electrostatic field is established according to voltages applied to the respective metal electrodes
101
inside a space
107
surrounded by internal surfaces
101
a
of the respective metal electrodes
101
. Accordingly, the charged particle beam passing along the center axis Z in the space
107
is deflected according to the electrostatic field established in the space
107
.
Each of clearances
108
between adjacent metal electrodes
101
is not of the shape of a straight line, but of the shape bent twice and then reaching the insulating sheath
102
. This is for the purpose of keeping exposed portions
109
of the insulating sheath
102
off direct view from the charged particle beam passing the space
107
. This structure prevents charge-up of the insulating sheath
102
and allows the electrostatic field in the space
107
to be precisely controlled by the voltages applied to the respective metal electrodes
101
.
SUMMARY OF THE INVENTION
The above electrostatic deflector
100
, however, had the problems of the complex structure, the large number of components, and difficulties in reduction of cost and size.
The octupole metal electrodes
101
constituting the electrostatic deflector
100
are constructed by first screwing a metal cylinder to the inside of the insulating sheath
102
and dividing the cylinder into the electrodes. For this reason, it was difficult to enhance dividing angle accuracy of the metal electrodes
101
. For the same reason, it was also difficult to enhance the circularity of the space
107
surrounded by the internal surfaces
101
a
of the metal electrodes
101
.
Thus proposed recently was use of film electrodes deposited on an insulator by a surface treatment of plating or the like (plating electrodes) instead of the above metal electrodes
101
(for example, as described in Japanese Patent Application Laid-Open No. H02-247966). The electrostatic deflectors using the plating electrodes obviate the need for screwing of the electrodes, which can decrease the number of components and decrease the size.
In the electrostatic deflectors using the plating electrodes, if the voltage-applying wires are directly fixed to the plating electrodes by screwing as in the case of the conventional electrostatic deflector
100
described above, the surfaces of the plating electrodes can be perforated with holes. If the plating electrodes should have holes the electrostatic field distribution could be distorted in the space in which the charged particle beam passes, and it would result in failing to control deflection of the charged particle beam with high accuracy.
For this reason, the electrostatic deflector disclosed in the application Laid-Open No. H02-247966 is constructed to prevent the surfaces of the plating electrodes from being perforated in such a manner that support portions of an insulator with the plating electrodes formed thereon are projected out, together with the plating electrodes, from an end of the insulating sheath and that the voltage-applying wires are connected to the projecting portions. However, this wiring structure was complex and there was the possibility that coatings (insulator) of the voltage-applying wires connected to the projecting portions could be viewed through clearances between adjacent plating electrodes.
There were also desires for construction using the plating electrodes in the other charged particle beam control elements (such as the electrostatic lenses and the like) as well as the aforementioned electrostatic deflectors. Under such circumstances, there were desires for some idea about how to connect the voltage-applying wires to the plating electrodes.
An object of the present invention is to provide a charged particle beam control element enabling the connection of the voltage-applying wires to the electrodes in simple structure while maintaining the surfaces of the electrodes formed on the insulator by the surface treatment of plating or the like with high accuracy, a method of fabricating the charged particle beam control element, and a charged particle beam apparatus.
A charged particle beam control element according to the present invention is a charged particle beam control element for controlling a trajectory of a charged particle beam by an electrostatic field, which comprises: a cylindrical base having a plurality of electrode portions formed on an internal surface thereof; and insulating portions, which are disposed at respective locations not exposed to a passing area of the charged particle beam surrounded by the internal surface, separate the electrode portions from each other.
Since the plurality of electrode portions formed on the internal surface are separated from each other by the insulating portions in this way, the internal surface defining the passing area of the charged particle beam can be readily machined in any desired shape. Since the insulating portions are not exposed to the passing area of the charged particle beam, the charged particle beam can be controlled more accurately without charging the insulating portions up by the charged particle beam.
The above charged particle beam control element may also be so configured that a plurality of grooves extending from one end to the other end of the base are formed on the internal surface and that a cross-sectional shape of each groove is bent and each insulating portion is formed in a deepest area of the groove.
When the insulating portions are formed in the grooves extending from one end to the other end of the base in this way, the electrode portions formed on the internal surface can be separated from each other. When the insulating portion is formed in the deepest area of each bent groove, the insulating portion can be kept from being exposed to the passing area of the charged particle beam.
The above charged particle beam control element may also be so configured that a through hole is formed so as to penetrate the base between a peripheral surface of the base and each groove and that an electroconductive portion is formed on an internal surface of the through hole.
When the conductive portion is formed on the internal surface of the through hole penetrating the base from the peripheral surface to the groove, it becomes unnecessary to form the conductive portion on the internal surface defining the passing area of the charged particle beam and thus it becomes feasible to keep the internal surface smooth. When the through hole is used as a screw hole for fixing the base, the structure of the charged particle beam control element can be simplified.
The above charged particle beam control element may also be so configured that the through hole is not exposed to the passing area of the charged particle beam.
When the through hole is formed so as not to be exposed to the passing area of the charged particle beam in this way, it becomes feas
Hashmi Zia R.
Lee John R.
Nikon Corporation
Oliff & Berridg,e PLC
LandOfFree
Charged particle beam control element, method of fabricating... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Charged particle beam control element, method of fabricating..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Charged particle beam control element, method of fabricating... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3336182