JPH0456419B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a focused ion beam, and more particularly to a device that allows maskless ion implantation, pattern writing, etc. to be performed under optimal conditions in one device. .

[Prior art] In a focused ion beam device using a liquid ion source, Ga (gallium) and Au (gold) are
Including, Si (silicon), Be (beryllium),
Since a wide variety of metal ions such as B (boron), Zn (zinc), and Sb (antimony) can be obtained, it has a wide range of applications in semiconductor processes, such as maskless ion implantation, resist direct writing, etching, and mask repairers. It's on. FIG. 4 is a diagram showing an example of the configuration of a conventional focused ion beam device used in such a semiconductor process. In the figure,
1 is an accelerated ion beam; 2 is an objective lens composed of an electrostatic lens and focuses the ion beam onto a sample, which will be described later; 3a and 3b are drawing deflectors arranged above the objective lens and supplied with a deflection signal. 4 is the sample that will finally be irradiated with the ion beam, and 5 is the oblique irradiation device that is placed between the objective lens and the sample in order to tilt the ion beam at a 7° angle and irradiate the sample. It is a deflector for

To perform maskless ion implantation using the conventional apparatus configured as described above, in order to suppress the channeling effect of the sample 4, a DC voltage is applied to the deflector 5 for oblique irradiation from a DC power supply (not shown), and the ion beam is It is injected into sample 4 at an angle of approximately 7° to the vertical direction. Here, the channeling effect refers to a phenomenon in which, for example, when an ion beam enters between the lattice intervals of a lattice-like atomic arrangement of a Si single crystal, it penetrates deeply without colliding with Si atoms. To avoid this, the ion beam is irradiated obliquely.

[Problems to be solved by the invention] By the way, in the conventional device configured as described above,
The ion beam is irradiated onto the sample at a 7° angle.
It is possible to perform resist direct writing, etching, mask repairer, etc.
An ion beam deflected at such a large angle has a larger ion beam diameter (probe diameter) than an ion beam that is incident perpendicularly. Therefore, if resist direct writing, etching, mask repairer, etc. are performed with the ion beam tilted, accurate writing may become impossible in resist direct writing, which requires the ion beam diameter to be made as small as possible, or etching may occur. , mask repairers, etc. have the disadvantage that they cannot accurately control the amount of etching or mask correction.

The present invention has been made in view of the above points, and an object of the present invention is to enable multipurpose applications such as maskless ion implantation, resist direct writing, etching, and mask repairer with a single focused ion beam device. In less ion implantation, the ion beam is tilted at a 7° angle to irradiate the sample, suppressing the so-called channeling effect and keeping the ion implantation amount constant.Also, when used for resist direct writing, etc., the ion beam is tilted at a 7° angle to the sample. The object of the present invention is to provide an apparatus that performs accurate drawing by vertically irradiating ion beams and minimizing the diameter of the ion beam.

[Means for Solving the Problems] The configuration of the present invention for achieving the object of the present invention includes a pattern drawing deflector provided above an objective lens for scanning an ion beam on a sample; The objective lens for irradiating the sample with the beam obliquely and a deflector for oblique irradiation provided between the sample, and a DC voltage applied to the deflector for oblique irradiation based on a selection signal. It is characterized by being configured to turn on/off.

[Example] Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. The same reference numerals are used for the same parts as in FIG. 1st
In the figure, 6 is a scanning signal generator that supplies scanning signals to the writing deflectors 3a and 3b via amplifiers 7a and 7b, and 8 is a scanning signal generator that applies a DC voltage to the oblique irradiation deflector 5 to tilt the ion beam. 9 is a switch circuit that turns on/off the DC voltage applied to the deflector 5 for oblique irradiation, 10 is a control circuit that controls the scanning signal generation circuit 6 and the switch circuit 9, and 11 is a control circuit 10. This is an operation panel for instructing ion implantation or other drawing operations.

In such a configuration, when maskless ion implantation is selected by the operation panel 11, the control circuit 10 controls the switch circuit 9 to
a is turned on, and switch 9b is turned off. Due to this control, a DC voltage is applied from the DC power source 8 to the tilting deflector 5, so that the ion beam 1 is directed toward the sample 4 as shown in FIG.
It is scanned by the drawing deflectors 3a and 3b while being tilted at 7 degrees. Therefore, ion implantation can be performed while preventing the channeling effect of the sample 4. When writing other than ion implantation, such as resist direct writing, is selected using the operation panel 11, the control circuit 10 controls the switch circuit 9 to turn off the switch 9a and turn on the switch 9b. By this control, the deflector 5 for oblique irradiation is kept at the ground potential, and the scanning signal generator 6 supplies the scanning signal to the deflectors 3a and 3b for drawing, so that the ion beam as shown in FIG. Since the beam 1 is scanned in an untilted state, that is, in a state in which the sample 4 is irradiated with the ion beam substantially perpendicularly, the ion beam diameter can be made as small as possible. Therefore, accurate writing is possible in resist direct writing, and etching amount or mask correction can be accurately controlled in etching, mask repairer, etc.

Note that the above embodiments are merely illustrative, and the present invention can be implemented in other embodiments. In the above embodiment, the deflector for oblique irradiation is configured with one stage, but may be configured with two stages in order to reduce chromatic aberration. In this case, the applied DC voltage may be controlled to be turned on/off simultaneously. Alternatively, the inclination angle of the ion beam may be controlled by controlling the DC power supply in conjunction with the accelerating voltage.

[Effects of the Invention] As explained in detail above, according to the present invention, 1
This focused ion beam device enables multi-purpose applications such as maskless ion implantation and resist direct writing. Maskless ion implantation prevents the so-called channeling effect, and resist direct writing allows the ion beam to be applied directly to the sample. Since the ion beam can be irradiated vertically and the diameter of the ion beam can be made as small as possible, an apparatus is provided that can perform accurate drawing and the like.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG.
FIG. 3 is a diagram for explaining the present invention, and FIG. 4 is a diagram showing a conventional example. 1: Ion beam, 2: Objective lens, 3a, 3
b: Deflector for drawing, 4: Sample, 5: Deflector for oblique irradiation, 6: Scanning signal generator, 7a, 7b: Amplifier, 8: DC power supply, 9: Switch circuit, 10: Control circuit, 11: Operation panel.

Claims (1)

[Claims] 1. A graphic drawing deflector provided above an objective lens for scanning an ion beam on a sample, and the objective lens and sample for irradiating the sample with the ion beam at an angle. A focused ion beam device comprising: a deflector for oblique irradiation provided in between, and configured to turn on/off a DC voltage applied to the deflector for oblique irradiation based on a selection signal. 2. The focused ion beam device according to claim 1, wherein the ion beam is tilted by 7 degrees by a DC voltage applied to the oblique irradiation deflector and irradiated onto the sample. 3. The focused ion beam device according to claim 1 or 2, wherein the oblique irradiation deflector has a two-stage configuration.