JPH01169860A - Charged particle beam device - Google Patents

Abstract

PURPOSE:To shorten the working distance between an objective lens and a target and improve the convergence characteristic of a charged particle beam by providing a gap on a micro-channel plate and arranging a gas feeding pipe through this gap. CONSTITUTION:This device is provided with a focusing lens to focus a charged particle beam 1 generated and accelerated from a charged particle beam source, a target 8 radiated by the charged particle beam 1, and a pipe 17 to guide the gas to the surface of the target 8. A micro-channel plate 21 detecting electrons generated due to the radiation of the charged particle beam 1 to the target 8 is provided, a gap is provided on the micro-channel plate 21, and the pipe 17 is arranged through this gap. No installation space of the gas pipe is thereby required to be provided, the working distance can be shortened, the convergence characteristic of an electron beam can be improved.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a charged particle beam device that irradiates a target with an electron beam or an ion beam, and particularly relates to a charged particle beam device that irradiates a target with an electron beam or an ion beam. The present invention relates to a charged particle beam apparatus suitable for etching a target by spraying a gas such as ) or for performing deposition by spraying an organometallic gas.

[Prior art] Fig. 4 shows that while a target is irradiated with an electron beam,
This figure shows a gas-assisted etching device that sprays chlorine gas, and numeral 1 in the figure represents an accelerated electron beam generated from a charged particle beam source (not shown). Reference numeral 2 denotes an electrostatic type objective lens, and the objective lens 2 consists of an outer electrode 3 at a ground potential and a center electrode 5 to which a lens voltage is applied from a lens electrode 8!4. 6 is an electrostatic deflection plate in the X direction, 7 is an electrostatic deflection plate in the Y direction, 8 is a target to which the electron beam 1 is irradiated, 9 is an auxiliary electrode, and 10 is an electrostatic deflection plate for the target 8 and the auxiliary electrode 9. This is the power source that provides beam deceleration potential. 11 is a microchannel plate for detecting secondary electrons generated when the electron beam is irradiated to the target 8; 12 is a detection electrode; the secondary electron emission surface 11b of the microchannel plate 11;
is maintained at the same potential as the detection electrode 12, and a voltage of 1 to 1.2 kV is applied from a power source 13 between the emission surface 11b and the secondary electron incident surface 11a of the microchannel plate. Moreover, the target 8 and the secondary electron entrance surface 11a
A voltage of about 100V is applied from the power supply 14 between the two. The secondary electron detection signal obtained from the detection electrode 12 is amplified by a preamplifier 15 and supplied to a light emitting diode 16. 17 is a gas supply pipe connected to a chlorine gas source (not shown), and 18 is a needle valve for controlling the gas m blown from the pipe 17 to the target 8.

A shield tube 19 prevents the electric field in the electron beam path from being disturbed due to movement of the target, preventing the electron beam from being improperly deflected, and preventing the focusing of the electron beam from being disturbed.

In the configuration as described above, the electron beam 1 is irradiated onto the target 8, and chlorine gas is supplied to the electron beam irradiation point of the target 8 via the gas pipe 17, so that the electron beam is irradiated. The target area is etched.

The electron beam irradiation point on the target is set by an electrostatic deflection plate 6.
It is possible to change the voltage according to the voltage supplied to the electrode 7, thereby making it possible to perform fine pattern etching. Here, the electron beam 1 is accelerated with an accelerating voltage of, for example, -30 kV, and enters the objective lens 2 with relatively high energy, so that the electron beam 1 is narrowly focused on the target 8.

Here, a deceleration voltage of, for example, -27 kV is applied to the target 8 and the auxiliary electrode 9 from the electric rA10,
As a result, an electron beam deceleration electric field is formed between the ground potential outer electrode 3 of the objective lens 2 and the auxiliary electrode 9, and the energy of the electron beam is lowered to reach the target 8.
will be irradiated. That is, the acceleration voltage of the electron beam irradiated onto the target 8 is substantially -3 kV.

In this way, in the apparatus shown in Fig. 4, the electron beam enters the electrostatic lens in a high energy state and is narrowly focused, while the electron beam is directed to the target 8 with low energy, which is optimal for gas-assisted edging. will be irradiated.

In the apparatus shown in FIG. 4, secondary electrons generated by irradiating the target 8 with an electron beam are guided to the microchannel plate 11 and amplified, and the electrons emitted from the microchannel plate 11 are transferred to the detection electrode 12. It is detected by The signal from the detection electrode 12 is sent to the amplifier 1
5 is amplified by the target 8 and then supplied to the light emitting diode 16.
It emits light depending on the electron intensity. Light from the diode is detected by a photodetector (not shown). As a result, the electron beam 1 is scanned by the deflection plate 6.degree. 7, and the focus state of the electron beam on the target 8 can be known from the secondary electron signal detected in accordance with the scanning.

[Problems to be Solved by the Invention] In the above-described configuration, the deflection plates 6 and 7, the microchannel plate 11, and the gas supply pipe 17 are arranged between the objective lens 2 and the target 8. The distance between objective lens 2 and target 8 is 1! (working distance) becomes long, and therefore there is a limit to improving the focusing characteristics of the electron beam. Although we have described a gas-assisted etching device that uses an electron beam, in a gas-assisted etching device that uses an ion beam, there are also deflection plates, microchannel plates, gas pipes, etc. between the objective lens and the target, just like in the case of electron beams. are arranged, and the focusing characteristics of the ion beam are not necessarily satisfactory. Furthermore, even with gas-assisted deposition equipment that supplies organometallic gas to the irradiation point of electron beams or ion beams rather than gas-assisted etching equipment, the working distance becomes long for the same reason, and it is difficult to improve the beam focusing characteristics. There is a limit.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a charged particle beam device that can improve the focusing characteristics of electron beams and ion beams.

[Means for Solving the Problems] A charged particle beam device based on the present invention includes a focusing lens for focusing a charged particle beam generated from a charged particle beam source and accelerated, and the charged particle beam is irradiated with the focusing lens. The method includes a target, a pipe for guiding gas to the surface of the target, and a microchannel plate for detecting electrons generated based on irradiation of the target with a charged particle beam, and a gap is provided in the microchannel plate. , the pipe is arranged through the gap.

[Example] An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

1 and 2 are sectional views of essential parts showing one embodiment of the present invention, FIG. 1 is a sectional view taken along line AA in FIG. 2, and FIG. 2 is a sectional view taken along line B-8 in FIG. This is a cross-sectional view, and the same or similar components in the figure as in FIG. 4 are given the same numbers and detailed explanation thereof will be omitted. In this embodiment, 21 is a microchannel plate, and the microchannel plate 21 is divided into two parts, and a gas supply pipe 17 is arranged in the gap between the two parts. Note that a shield plate 22 is arranged at the divided portion of the microchannel plate 21 in order to alleviate the electric field.

With this configuration, compared to the conventional device shown in FIG. 4, there is no need to provide a space for arranging the gas pipe 17, the working distance can be shortened, and the focusing characteristics of the electron beam can be improved.

FIG. 3 shows another embodiment of the invention. In this embodiment, a hole 32 is bored in the microchannel plate 31, and the gas supply pipe 17 is placed through the hole. In this embodiment as well, the microchannel plate can be brought closer to the target 8 in order to shorten the working distance. Furthermore, in this embodiment, since the pipe 17 can be fixed to the auxiliary electrode 9 near the gas outlet, the gas pipe can be supported more stably than in the past.

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to these embodiments and can be modified in many ways.

For example, although the description has been given of an apparatus that etches a target by spraying an active gas such as chlorine gas onto the target surface, the present invention can also be applied to a gas-assisted deposition apparatus that sprays an organic metal gas. Further, although the case where an electron beam is irradiated has been described, the present invention can also be used when a target is irradiated with an ion beam. Furthermore, although the electron beam is decelerated, deceleration of the charged particle beam is not an essential requirement in the present invention.

[Effects] As detailed above, in the present invention, a gap is provided in the microchannel plate and the gas supply pipe is arranged in this gap, so the working distance between the objective lens and the target can be shortened. The focusing characteristics of the charged particle beam can be improved.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of one embodiment of the present invention;
This figure is a sectional view showing another embodiment of the present invention, and FIG. 4 is a view showing a conventional gas assisted etching apparatus. 1...Electron beam 2...Objective lens 3...
・Outer electrode J...Center electrode 4.10.13
．． 14... Power supply 6.7... Electrostatic deflection plate 8... Target 9... Auxiliary electrode 11.2
1.31... Microchannel plate 12... Detection electrode 15... Amplifier 16...
・Light-emitting diode 17...Pipe 18...Twenty dollar bulb 19...Shield tube

Claims (3)

[Claims] (1) A focusing lens for focusing the accelerated charged particle beam generated from the charged particle beam source, a target to which the charged particle beam is irradiated, a pipe for guiding gas to the surface of the target, and the target. a microchannel plate for detecting electrons generated based on irradiation of a charged particle beam with a charged particle beam, the microchannel plate is provided with a gap, and the pipe is arranged through the gap. line equipment. (2) The charged particle beam device according to claim 1, wherein the microchannel plate is divided into parts, and the pipe is arranged in a gap between the divided parts. (3) The charged particle beam device according to claim 1, wherein the microchannel plate has a hole, and the pipe is disposed through the hole.