JPS60210830A - Electron beam annealing apparatus - Google Patents

Abstract

PURPOSE:To realize beam line and excellent convergence of beam by providing a high speed deflection electrode for forming a line of electron beam in the side of sample to be annealed than the lens or coil of the final stage. CONSTITUTION:A high speed deflection electrode 59 for forming a line of electron beam is placed under a deflection coil 58, namely under the coil of lowest stage. Thereby, the annealing by electron beam can be efficiently executed under the maximum condition. In case an electrode 59 is provided between a coil 58 and a second lens 57, beam speed is different at the center and both ends of line beam and the beam is curved like an arc in the course of path. Meanwhile, in case the electrode 59 is placed on the lens 57, convergence is little different at the center of line beam and both ends thereof and it is very diffucult to set the focus in both areas. On the other hand, this apparatus forms a line of beam and ensures excellent characteristics of convergence and scanning.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electron beam annealing device, and in particular, an electron beam annealing device that has a function of linearizing the beam shape using a pair of flat electrodes and a high frequency voltage applied thereto. Regarding a beam annealing device.

[Technical background of the invention and its issues]

In recent years, beam annealing equipment has been developed that uses energy beams such as electron beams and laser beams to heat-treat (anneal) semiconductor samples such as Si, Ge, and GaAS, metal samples such as AI, MO, and W, and metal compound samples. is being developed. Using this device, samples can be sampled for a short period of time.
By locally annealing, semiconductor devices can be made faster, more highly integrated, and more multifunctional, opening up the possibility of realizing devices with new functions and new structures.

FIG. 1 is a schematic configuration diagram showing a conventional electron beam annealing apparatus, in which 11 is a sample chamber, 12 is an optical barrel, 13 is an electron gun, 14.15 is a lens, 16 is a deflection coil, and 17
indicates a sample, and 18 indicates a sample stage. In this device, the electron beam emitted from the electron gun 13 is passed through the lens 14.
．． 15 and scans the beam on the sample 17 using the deflection coil 16 to anneal the sample 17.
For example, epitaxial growth, melt recrystallization, etc. are performed.

However, this type of device has the following problems. That is, it is necessary to make the solid-liquid interface of the silicon layer on the insulating film convex with respect to the beam traveling direction. However, annealing using an electron beam with a Gaussian distribution has not been able to form a solid-liquid interface that is convex in the direction of movement. In addition, in the figure, A indicates the beam scanning direction, and B
indicates a melting region, C indicates a grain boundary, and D indicates a recrystallized region. On the other hand, in conventional electron beam annealing equipment, the spot beam (melting beam diameter ~1°0 μm) is continuously scanned and overlaid appropriately to perform 7 anneals on the entire surface, but the annealing time using this method is It takes a long time and is hardly practical.

As a means to solve these problems, the present inventors developed a method of linearizing the electron beam by rapidly deflecting the electron beam in a direction (Y direction) perpendicular to the scanning direction (X direction) of the beam. proposed. This can significantly reduce the time compared to a single stop. Furthermore, by combining linear beams or by making the high-speed deflection electrode curved, it is possible to form a solid-liquid interface that is convex in the beam traveling direction as shown in FIG. be.

By the way, as a result of further intensive research by the present inventors regarding annealing using such a linearized beam, the following facts were discovered. In other words, although we thought that the position of the high-speed deflection electrode for linearization was not very important in linearizing beam b, it had an extremely important effect on beam focusing, scanning performance, etc. It turns out. In other words, it has been found that the focusing and scanning properties of the electron beam are significantly reduced depending on the placement position of the high-speed deflection electrode.

(Object of the Invention) The object of the present invention is to linearize the beam 7 and to obtain extremely good focusing and scanning characteristics. If a high-speed deflection electrode is provided, its mounting position should be at the deflection coil 16.
There are various possibilities such as below, between the deflection coil 16 and the objective lens 15, above the objective lens 15, etc., but according to the actual scissors of the present inventors, the aberration of the lens becomes large above the objective lens 15, and the deflection coil It was found that the beam convergence deteriorates above 16. Further, at a position below the deflection coil 16, the aberration of the lens is small and the beam focusing property is good, and the scanning performance of the beam using the deflection coil 16 is also extremely smooth, and scanning unevenness etc. can be effectively eliminated. I found out.

The present invention has been made in view of these circumstances, and applies a voltage varying by high-frequency sine waves, triangular waves, etc. to two flat electrodes (high-speed deflection electrodes) IO placed opposite to each other. In an electron beam annealing device that can deflect an electron beam at high speed into a linear beam, it is possible to linearize the beam by using the high-speed deflection electrode provided below the final stage lens or coil. In addition, the beam focusing and scanning properties are extremely good. Therefore, optimal annealing of the sample can be performed. This is extremely effective when a semiconductor film on an insulating film is made into a single crystal by electron beam annealing, and is extremely effective when applied to the manufacture of three-dimensional ICs and the like.

[Embodiments of the invention]

FIG. 5 is a schematic configuration diagram showing an electron beam annealing apparatus according to an embodiment of the present invention. In the figure, 51 is an evacuated sample chamber, and 52 is an electron optical a cylinder. A movable sample stage 53 is arranged within the sample chamber 51, and a sample 54 is placed on this stage 53. Inside the optical lens barrel 52, an electron gun 55. A second lens 57 for beam focusing and a second lens (objective lens) 57. Scanning deflection coil 58. High-speed deflection electrodes 59 for beam linearization are provided respectively. The electron beam emitted from the electron gun 55 is focused by lenses 56 and 57, linearized by a high-speed deflection electrode 59, and scanned over the sample 54 by a deflection coil 58. It is supposed to be completed 7 times.

In this embodiment, the fast deflection electrode 59 for beam linearization is placed below the deflection coil 58, that is, below the final stage coil. This maximizes the effects of the present invention. According to a series of experimental results that investigated the relationship between the position of the high-speed deflection electrode 59 and the electron beam annealing characteristics,
First, if the high-speed deflection electrode 59 is installed between the deflection coil 58 and the second lens 57, a problem will occur in beam scanning, and the beam speed will be different between the center and both ends of the linear beam, and the beam will be distorted in the middle. It turns out that it becomes arched. On the other hand, if the high-speed deflection electrode 59 is placed on the second lens 57, a problem arises in beam focusing. That is, the convergence conditions at the center and near both ends of the linear beam are slightly different, and it is extremely difficult to bring them both confocal. Therefore, when a silicon film on an insulating film is made into a single crystal by electron beam annealing, non-uniform crystal growth occurs, which in turn causes problems in device characteristics.

On the other hand, in the apparatus of this embodiment, all of the above problems were solved, so that electron beam annealing could be performed efficiently under the best conditions, and the uniformity and reproducibility of annealing could be improved.

The following is a diagram showing how this device is used in the manufacture of MOS-LSI (Fig. 6).
As shown in a), for example, a 5102 film 62 having a thickness of about 1 [μTrL] is formed on a single crystal silicon substrate 61 of P type (100) plane orientation, and a SiN layer 63 is formed thereon as required. This SiN layer 63 is intended to facilitate single crystallization of a polycrystalline or amorphous silicon layer in a later step, and is not necessarily necessary. Next, as shown in FIG. 6(b), a polycrystalline silicon layer 64 of approximately 6,000 layers is deposited on the SIN film 6, and a 5,102 layer 65 of approximately 2,000 layers is formed thereon. . Here, the SiO2 film 6
Reference numeral 5 is for facilitating single crystallization of the polycrystalline silicon layer 64 in a later step, and may be a SiN film.

Next, using the embodiment shown in FIG. 5, the apparatus shown in FIG.
As shown in C), the sample is irradiated with an electron beam to single-crystallize the silicon layer 64. At that time, the acceleration voltage of the electron beam was set to 10 [KelV], and the beam current was set to 5 [mA]. The width of the silicon layer 64 melted during annealing is approximately 50 [
μTrL]. By repeating beam scanning, the crystal grains gradually decrease, making melting and recrystallization extremely smooth, and effectively single-crystallizing silicon without any problems such as uneven heat treatment, untreated areas, or silicon evaporation. was completed.

Next, as shown in FIG. 6(d), after removing the SiO2 film 65, the silicon layer 64', which has been single-crystalized by beam annealing, is patterned to form a second layer element formation region using a well-known technique. An insulating film 66 for element isolation is formed. Subsequently, a polycrystalline silicon gate electrode 68 is formed on the silicon layer 4' via a gate oxide film 67, and source/drain regions 69a and 69b are further formed to complete a MOS transistor. Next, as shown in FIG. 6(e), after covering the entire surface with an insulating film 70, an A1 wiring layer 71a,
By forming 71b and 71c, MOS-LSI
is completed.

The configuration of the H cylinder is not limited to that shown in Figure 5.
However, as long as the high-speed deflection electrode is placed closer to the sample than the final stage lens or coil, changes can be made as appropriate depending on the specifications. For example, the high-speed deflection electrode may be formed into a curved surface to form a curved beam so that the solid-liquid interface is convex with respect to the beam traveling direction. Furthermore, two optical barrels may be used to combine the linear beams to form a beam r<J. Furthermore, the voltage applied to the high-speed deflection electrode is not limited to a sine wave, a triangular wave, etc., and may be any high frequency voltage that is sufficiently high relative to the beam scanning speed on the sample. In addition, various modifications can be made without departing from the gist of the present invention.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing a conventional electron beam annealing device, and Fig. 2 is a schematic configuration diagram showing an electron beam annealing device related to a schematic diagram showing how grain boundaries appear in recrystallization using a conventional spot beam. Ru. 51... Sample chamber, 52... Electron optical column, 53...
・Sample stage, 54...sample, 55...electron gun,
56... First focusing lens, 57... Second focusing lens (objective lens), 58... Deflection coil for beam scanning, 59... High speed deflection electrode. Applicant: Director of the Agency of Industrial Science and Technology Hirobe Yoda Figure 1 Figure 2 Figure 4 (a) (b) Figure 6 Figure 6

Claims (1)

[Claims] An electron gun that emits an electron beam, a lens system that focuses the electron beam emitted from the electron gun, a scanning deflection system that scans the beam on a sample, and a scanning deflection system that deflects the beam at high speed to linearize it. 1. An electron beam annealing apparatus comprising: a high-speed deflection electrode, the high-speed deflection electrode being raised closer to the sample than a final stage lens or coil.