JPH0812771B2 - Electron beam processing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electron beam processing apparatus, and more particularly to an electron beam processing apparatus used for annealing a semiconductor film such as an SOI film or welding or processing a mechanical part.

[Prior Art] When annealing a semiconductor film or welding or processing a mechanical part using an electron beam, a method of deflecting the electron beam by a deflector and scanning the sample for processing is usually used. . The deflection wave used at this time is a simple ramp wave.

[Problems to be Solved by the Invention] The processing apparatus having the above-described conventional electron beam deflector and power supply has the following problems. That is, in the conventional processing apparatus, since the deflection is performed by a simple ramp wave, the temperature gradient in the scanning direction of the electron beam cannot be freely changed. Although it is possible to change the temperature gradient to some extent by changing the scanning speed of the beam, it is difficult to change the scanning speed largely in consideration of the power density of the beam. On the other hand, it is possible to change the apparent intensity distribution with respect to the scanning direction of the beam by modulating the ramp wave with a certain frequency. This method is an excellent method for controlling the temperature gradient. The disadvantage is that it has to be modulated with a rather complex waveform for free control.

An object of the present invention is to solve such conventional problems and to provide an electron beam processing apparatus capable of controlling a temperature gradient in the scanning direction of an electron beam.

[Means for Solving the Problems] In the present invention, the means for achieving the above-mentioned objects and solving the problems are as shown in FIG. In the electron beam processing apparatus that deflects light by 5 and scans the sample 6 to perform various processes, a pulse wave generator 10 that generates a short pulse with a variable pulse length and pulse height and an electron beam on the sample 6 A ramp wave generator 11 for scanning, a mixer 12 for mixing the output signals of the pulse wave generator 10 and the ramp wave generator 11 and applying them to the deflector 5, and a temperature monitor 13 for measuring the sample temperature.
And an electron beam processing apparatus including a control system 14 for controlling the pulse wave generator 10.

[Operation] When an electron beam having a Gaussian distribution, for example, is reciprocated in the same direction as the scanning direction at a high speed in the scanning direction of the electron beam, it is possible to give a distribution other than the Gaussian distribution in appearance in the scanning direction. The present invention is basically based on this principle. FIG. 2 is an explanatory view showing the basic principle of the present invention, and FIG. 2 (a) shows one cycle of a pulse train for reciprocating the electron beam at a high speed. The pulse wave generator 10 shown in FIG. Is output. FIG. 6B shows the apparent intensity distribution, and FIG. 6C shows the temperature distribution realized on the sample by the electron beam of FIG.
When the electron beam is reciprocally moved by the pulse train of FIG. 7A, time corresponds to the existence probability (intensity) and the amplitude corresponds to the deflection amount (position), so that the intensity distribution shown in FIG. A, B, C, and D in FIG.
Corresponds to B, C and D respectively. When the sample is scanned with a beam having the beam intensity distribution shown in FIG. 2B, the temperature distribution becomes smooth due to thermal diffusion, and the temperature distribution in FIG. 3C can be realized on the sample. When the intensities of B, C, and D are changed by changing the pulse train, the temperature gradient of the G part in FIG. 7C can be changed freely.

EXAMPLES Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a configuration diagram of an apparatus for carrying out the present invention. In the figure, the electrons emitted from the cathode 1 through the grid 2 are accelerated by the anode 3, converged by the electron lens 4, and form an image on the sample 6. A signal obtained by adding the outputs of the pulse wave generator 10 and the ramp wave generator 11 by the mixer 12 is applied to the deflection electrode 5. At this time, if the period of the pulse train output from the pulse wave generator 10 is sufficiently short, for example, 0.1 μsec, the beam intensity has apparently a plurality of peaks in the scanning direction according to the principle described in FIG. When the pulse length of any one of the pulse trains output from the pulse wave generator 10 is changed, the intensity of the peak corresponding to the pulse changes. Further, when the pulse height is changed, the peak position changes. In the figure, 13 is a temperature monitor, which monitors the temperature of the sample by the light emission on the sample 6. This temperature signal is sent to the pulse control system 14, and for example, the pulse train is controlled so that the optimum condition for recrystallization is obtained to obtain the optimum temperature distribution.

The SOI film was actually annealed by the electron beam processing apparatus of this example. The annealing conditions are as follows: electron acceleration voltage is 15 kV, beam current is 87 mA, scanning speed is 70 cm / sec, the beam shape is 5 mm × 0.1 mm in a rectangular cross section, and scanning is performed in the longitudinal direction of the cross section. Also, the apparent beam intensity distribution has three peaks, and the peak height (intensity) has a maximum value of 10
0% was 30% and 10%, and the distance between peaks was 0.05 mm. This condition was realized by setting the pulse length of the pulse train to 10: 3: 1. As a result of annealing the SOI film under the above conditions, the optimum temperature distribution was obtained on the sample and the SOI film with good crystallinity was obtained.

Although this embodiment relates to annealing of a semiconductor film, it can be applied to welding and processing of mechanical parts.

[Effects of the Invention] As described above, according to the electron beam processing apparatus of the present invention, the temperature gradient on the sample with respect to the scanning direction of the electron beam can be freely controlled, and as a result, annealing of the semiconductor film such as the SOI film is performed. Alternatively, an optimum temperature gradient can be selected when welding or processing the mechanical parts, and a high-quality SOI film can be obtained, and the welding strength and the processing accuracy of the mechanical parts can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the principle of the present invention. 1 ... Cathode, 2 ... Grid 3 ... Anode, 4 ... Electron lens 5 ... Deflection electrode, 6 ... Sample 7 ... Heating power supply, 8 ... Bias power supply 9 ... Acceleration power supply, 10 ... Pulse Wave generator 11 …… Ramp wave generator, 12 …… Mixer 13 …… Temperature monitor, 14 …… Pulse control system

Claims (1)

[Claims] 1. An electron beam processing apparatus for deflecting an electron beam by a deflector to scan a sample to perform various kinds of processing, and a pulse wave generator for generating a short pulse having a variable pulse length and pulse height, A ramp wave generator for scanning an electron beam on a sample, a mixer for mixing output signals of the pulse wave generator and the ramp wave generator and applying the mixture to a deflector, a temperature monitor for measuring a sample temperature, and An electron beam processing apparatus comprising: a control system for controlling a pulse wave generator.