JPS584257A - Scanning-type electron-beam annealing device - Google Patents

Abstract

PURPOSE:To enable an electron beam to be constantly irradiated on a sample under an optimal condition, and enable a homogeneous annealing treatment of the electron beam to be performed by detecting the surface temperature of the sample, comparing the detected temperature with a preset temperature, and varying and controlling the irradiation intensity of the beam according to thus given difference. CONSTITUTION:Both the detection signal of an infrared-ray detecting element 13 and the output signal of a synchronizing-signal producing circuit 14 are supplied to a phase detecting circuit 15. Both the detection output of the circuit 15, and standard temperature information sent from a standard-temperature detecting element 17 via an amplifier 16 are supplied to a complex circuit 13. After the temperature of a point of a sample 8 on which a beam is irradiated is detected with the complex circuit 13, the detected temperature information is supplied to a computer 20 via an interface 19. On the other hand, the computer 20, in which an anneal temperature is set beforehand, gives the difference between the above set temperature and the above detected temperature which is used as the input to the computer 20, and varies and controls the scanning speed of an electron beam or the bias of an electron gun 1 according to the avove difference.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to pagination in a scanning electron beam annealing apparatus. - Recently, the annealing technology manufactured by Atsui Kinkiri Co., Ltd., which heats the substrate surface using an electron beam or the like in a radar beam, has been attracting attention.

Among these, the scanning type electron V-Moore annealing has great practicality because it can uniformly heat the substrate surface and easily increase the crystal grain size and single crystallize silicon deposited on an amorphous material. We have each member.

FIG. 1 is a schematic diagram showing a conventional O-scanning heavy electron beam annealing system. In the figure, 1 is the cathode 2. An electron gun consisting of a Wehnelt electrode J and an anode 4III, 6
is the deflection hexagram for f ranking.

6 is a lens, 1 is a beam scanning deflector, a is a sample, and 9 is an XY stage. Then, the crossover P created by the electron gun 1 is placed on the lens-type sample 8 by Ili! fgII
has been done. In such an apparatus, the beam scanning area is as small as 10×IO (10×IO), so when heating a silicon wafer or the like having a diameter of 41 inches, the X-Y stage 9 is moved to anneal small areas at a time.

By the way, when the present inventors used the above-described apparatus to implant arsenic ions into deposited silicon and annealed nine samples, the results shown in FIG. 2 were obtained. In Figure 1i42, the horizontal axis represents time in seconds, and the vertical axis represents the iron surface resistance ρ [Ω] after annealing. Further, the acceleration voltage was set to 10 (kV). It took 1 second to anneal one small pile for 7 anneals, and it took about 300 seconds to anneal the entire 4-inch wafer. As is clear from Figure 2, as time tog passes, the resistance m
The surface resistance of the nine parts processed in the first half and the part processed later are significantly different. This was interpreted to be because the average temperature of the sample increased with the beam irradiation time, and the annealing effect was different between the region annealed first and the region annealed at time tl. The present inventors have found that this change in the average temperature of the sample with the annealing time is a major problem that hinders the practical application of electron beam annealing technology.

On the other hand, the effect of annealing strongly depends on the intensity of the electron beam current and the scanning speed of the beam, and it is extremely difficult to find the optimum value thereof. Also, even once you find the appropriate amount,
Inconvenient problems arise, such as unstable rounding of the contact area between the sample and the sample in the beam shape, and the optimum conditions being different in the next experiment.9.

The present invention has been made in consideration of the above circumstances, and
For that purpose, ζro is a scanning electron beam that can always irradiate the sample with the electron beam under optimal conditions and perform uniform annealing. - To provide a Moorea device.

That is, the present invention achieves the above object by detecting the surface temperature of the sample, comparing this detected temperature with a predetermined setting value, and variably controlling the beam irradiation amount according to the difference between them. It's a serious thing.

Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

FIG. 3 is a schematic diagram showing an embodiment of the present invention. Note that the same parts as those in 1E are given the same reference numerals, and detailed explanation thereof will be omitted. When the surface of the sample 80 is irradiated with an electron beam, the temperature of the beam irradiation point increases, and infrared rays R corresponding to the temperature are generated from the irradiation point. This infrared mouse is condensed by the condensing lens 11.
The light is guided to the infrared detection element IS via the infrared detection element IS. The detection signal of the infrared detection element 13 is supplied to the phase detection circuit 15 together with the output signal of the synchronization signal generation circuit 14. It is supplied to the threat circuit 18 together with the reference temperature information. The temperature of the beam irradiation point on the sample 8 is detected by the threat circuit 1a, and this detected temperature information is supplied to the computer 20 via the interface 19. Here, the infrared detection element 18. Phase detection circuit 1j, reference temperature detection element 16 and synthesis circuit 18
Since the operation of the non-contact temperature II@meter is well known, a detailed explanation thereof will be omitted.

On the other hand, the annealing temperature is set in advance in the computer 20, and the computer 20 calculates the difference between the set temperature and the input detection temperature, and adjusts the scanning speed of the electron beam according to this difference. The /4 ear of gun 1 is variably controlled. In the figure, 21 is a bias resistor switching circuit that switches the p-bias resistor 22 according to a command from the computer 20, 2J is a high-voltage power supply, 24 is a cathode heating power supply, 21 is a digital-to-analog converter, and 26 is an increase @ These vessels are well known and are no different from ordinary ones.

With such a configuration, the temperature at the beam irradiation point is first detected by the non-contact temperature measuring device, and this detected temperature Tm is sent to the computer 20. Then, the set temperature preset in the needle calculator 20 and the detected temperature gILTI11 are compared, and if the respective temperatures are different, the difference ΔT = Ts - Tm is determined. Then, the bias resistor 22 is switched in accordance with this difference ΔT, and the beam current is variably controlled, or the beam scanning speed is variably controlled. The current is controlled to be small or the beam speed is fast. As a result, the temperature of the irradiation point of the detection temperature minus one tnr-me is vigorously controlled by the set temperature τsK.

Therefore, according to the present apparatus, the beam irradiation point on the surface of the sample 80 can always be maintained at a constant set temperature TS, and the entire surface of the sample 8 can be subjected to a uniform 7-Ale process. Therefore, it is possible to prevent problems such as a change in the annealing effect due to an increase in the average temperature of the sample 8, which is a problem with conventional apparatuses. Furthermore, since the beam irradiation amount is automatically controlled to the optimum value, the practicality of the system is greatly improved.

Note that the present invention is not limited to the nine embodiments described above. For example, as the infrared detecting element, a current collecting lid or a photon type element may be used.
Since the condensing optical system becomes dirty due to the evaporation of the material, a protective film transparent to infrared rays may be provided over the entire surface of the condensing optical system O by means of a replacement tool. Further, the temperature detection point may not be located at the beam irradiation point, but may be a point scheduled to be irradiated with the beam in seconds. In this case, an increase in the average temperature of the sample will be detected.

Although it is most preferable to measure the temperature at the beam irradiation point, a sufficient effect can be expected even if the average temperature is constant. In addition, various modifications can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing a conventional device, 1lt2WA is a characteristic diagram for explaining the operation of the above device, and Fig. 3 is a zero firing r
FIG. 2 is a schematic configuration diagram showing an iso-embodiment. 1.- Electron gun, 5. Deflector for Tsutsuy Kinder, --. Lens, r-. Deflector for beam scanning, a-. Sample, 9...
X-Y stage, 1s-infrared detection element, 15... phase detection circuit, 11... reference temperature detection element, 18...
Synthesis circuit, 20... Computer, 21... Bias resistance switching circuit, 22 - Bias resistance, 23... High voltage power supply, zl... Digital-to-analog converter. Applicant's representative Patent attorney Hikosai Suzue

Claims (5)

[Claims] (1) In a scanning electron beam annealing procedure in which the electron beam is scanned over the sample and the sample IIm is annealed seven times,
Temperature detection means detects the surface temperature of the sample O without contacting the iron surface, and compares the detected detected temperature with a predetermined set temperature, and irradiates the sample Kjl according to the difference between these temperatures. 1. A scanning electron beam annealing apparatus, comprising: control means for variably controlling the beam irradiation amount. (2) Patent claim O characterized in that the temperature detecting means line is a line that detects the temperature of the irradiation point of the electron beam.
A scanning lid Ryuko beam annealing apparatus according to scope 1. (3) The scanning electron beam annealing device according to claim S, wherein the temperature detection means detects the temperature of the point irradiated with the beam after a predetermined time. (4) Patent claim 0, characterized in that the controller RIIi is a device that variably controls the scanning speed of the electron beam.
IIH Building Section 1 O Waterfall Inspection Electronic C-Moor Air Device. (5) The waterfall-type electron beam annealing apparatus according to claim 1, wherein the control means variably controls the bias resistance of the electron gun.