KR100849391B1 - Atomic force microscopy cantilever to possible reading/wrighting - Google Patents

Abstract

The present invention relates to a nuclear microscope cantilever capable of reading / writing, and more particularly, to a nuclear microscope cantilever capable of reading / writing information by embedding a MOSFET in the atomic microscope cantilever.

Readable / writeable atomic force microscope cantilever of the present invention comprises a cantilever support in which a metal layer, a first silicon layer, an oxide film, and a second silicon layer are sequentially stacked; A cantilever arm portion formed by extending only a second silicon layer of the cantilever support portion; A probe formed on a second silicon layer of the cantilever arm portion; A channel formed at the bottom of the probe; Sources / drains formed on both sides spaced apart from the center of the probe by a predetermined distance; And a gate formed between the source / drain.

Cantilever, Probe, Read / Write, MOSFET

Description

Atomic force microscopy cantilever to possible reading / wrighting}

1A and 1B are diagrams illustrating the atomic force microscope cantilever according to the present invention.

2 is a cross-sectional view showing a probe of a cantilever according to the present invention.

Figure 3 is a block diagram showing a nuclear microscope cantilever capable of reading / writing according to the present invention.

   <Description of the symbols for the main parts of the drawings>

100: first silicon layer 110: oxide film

120: second silicon layer 130: cantilever support

140: cantilever arm portion 150: probe

160: metal layer 170: channel

180: source 190: drain

200: gate

The present invention relates to a nuclear microscope cantilever capable of reading / writing, and more particularly, to a nuclear microscope cantilever capable of reading / writing information by embedding a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) in an atomic force microscope cantilever.

In general, the scanning probe microscope (SPM) has been developed into various types of microscopes capable of measuring various physical quantities by scanning probes.

One type of scanning probe microscope is an atomic force microscope (AFM) capable of measuring the amount of charge in a sample by using an atomic force between the probe and the sample.

Recently, many attempts have been made to use as a sensor for the next generation data storage using a probe having a field effect transistor structure embedded in a cantilever probe of an atomic force microscope.

Referring to Korean Patent No. 366701, which is a prior art, a transistor having a source and a drain formed on a probe by using only a micromachining process is formed to operate on a principle of detecting a region having a plurality of charge concentrations distributed on a sample. The probe was attached vertically to the insulator-formed sample, applying the voltage to the source, and measuring the current flowing through the drain according to the voltage change of the sample. In practice, no surface charge distribution has been read.

In addition, referring to Korean Patent No. 466157, which is a prior art, the operating principle is the same as that of No. 36701, but it has been improved to operate with a general atomic force microscope cantilever probe. This improves sensitivity by reducing the effective channel length between the source and drain, enabling the array to be configured with multiple probes in one body.

Therefore, when the cantilever is doped or coated with a metal thin film in a conventional atomic force microscope cantilever, the cantilever can be used to store and read a sample using charge. However, the method requires a lock-in amplifier while operating in contactless mode, which is very slow and very sensitive to changes in the surrounding environment.

The conventional technology as described above is a cantilever probe having a field effect transistor embedded therein, which is less sensitive to the surrounding environment and can read surface charges, and thus the charge distribution on the sample surface can be read well using the probe.

In addition, the channel length of the field effect transistor should be reduced to at least 100 nm or less, the current flowing in the drain should be very sensitive to the change of the charge amount of the sample, and it should be attached to this read function to be a write function probe. do. With this capability, only a single probe can be read and written, which can be used for terabit probe type information storage.

In addition, the cantilever probe of an atomic force microscope with a built-in field effect transistor is mainly used in the form of varying the amount of current flowing in the drain according to the change of the surface charge when passing the surface of the sample while applying a certain voltage to the source portion. have. The field effect transistor cantilever probe can be used as a read / write type probe by applying the same voltage as the source to the drain to perform a read function instead of using only the current flowing through the drain. There is the same problem.

First, the current flowing in the channel region between the source and the drain eventually moves toward the sample to perform a write function, so that the write method in the sample becomes a current control method. In this case, there was a problem that the amount of current cannot be adjusted accurately.

Second, there is a problem that the probe is easily worn by the continuous current flow in the pointed tip area.

Third, if the leakage current flowing between the source and the drain cannot be prevented, there is a problem in that unwanted data is always recorded in the sample storing data by the current flowing between the source and the drain.

Therefore, the above problems may not cause any problems in the case of a single probe, but the information storage device in the form of a probe cannot catch up with the speed of the current magnetic method in the form of a single probe. Have a big problem.

Accordingly, the present invention is to solve the above-mentioned disadvantages and problems of the prior art, it is possible to implement a read / write nuclear microscope cantilever to implement a read and write operation of information by embedding a MOSFET in the nuclear microscope cantilever It is an object of the present invention to provide.

The object of the present invention is a cantilever support unit in which a metal layer, a first silicon layer, an oxide film and a second silicon layer are sequentially stacked; A cantilever arm portion formed by extending only a second silicon layer of the cantilever support portion; A probe formed on a second silicon layer of the cantilever arm portion; A channel formed at the bottom of the probe; Sources / drains formed on both sides spaced apart from the center of the probe by a predetermined distance; And a read / write capable atomic force microscope cantilever comprising a gate formed between the source / drain.

Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1A and 1B are diagrams illustrating the atomic force microscope cantilever according to the present invention. As shown in FIGS. 1A and 1B, the cantilever of the present invention includes a cantilever support part 130 and a cantilever support part in which the first silicon layer 100, the oxide film 110, and the second silicon layer 120 are sequentially stacked. The metal layer formed on the cantilever arm portion 140 formed by extending the second silicon layer 120 of 130, the probe 150 formed on the second silicon layer 120 of the cantilever arm portion 140, and the cantilever support portion 130. 160, a channel 170 formed under the probe 150, a gate 200 formed between the source 180 and the drain 190 and the source 180 and the drain 190 formed on the left and right sides of the channel 170. ). Since the metal layer 160, the oxide film 110, and the second silicon layer 120 are sequentially stacked, the metal layer 160 has a MOS structure.

2 is a cross-sectional view of a probe of a cantilever according to the present invention. Referring to FIG. 2, the channel 170 is formed under the probe 150, and the source 180 and the drain 190 are formed on both sides of the channel 170, respectively. That is, since the source 180, the drain 190, the channel 170 and the probe 150 are included, it has a FET structure for atomic force microscopy.

Here, the source 180 and the drain 190 are formed by doping n-type impurities. When the source 180 and the drain 190 are formed by doping n-type impurities, the p-type impurities are doped in the channel 170. Should be.

To this end, if the channel 170 is masked using a second silicon layer doped with p-type impurities, and a high doping of impurities having a conductivity different from that of the doped second layer, the source 180 and the drain 190 ) Becomes the state of n ++.

The reason why the source 180 and the drain 190 are separated into a region doped with n ++ impurities as described above should be 100 nm or less in width for the channel 170 to be applied to a terabit probe type information storage device.

Figure 3 is a block diagram showing a nuclear microscope cantilever capable of reading / writing according to the present invention. Referring to FIG. 3, in the information reading according to the present invention, when a probe of an atomic force microscope MOSFET cantilever is brought into contact with a recording medium recorded as a charge accumulation, and a voltage Vs is applied to the source 180, the probe and the recording medium are applied. The current Id flowing through the drain 190 is read, and information recorded as '1' or '0' is read in the recording medium using the current value of the drain 190.

In the information writing according to the present invention, when the probe of the atomic force microscope MOSFET cantilever is brought into contact with the recording medium, a voltage Vg is applied to the metal layer 160 of the gate 200. At this time, the voltage Vg applied to the gate 200 is applied with + voltage when the impurities of the source 180 and the drain 190 are p-type, and-voltage when the impurities are n-type, and the channel ( 170) and charges are accumulated on the recording medium through the probe, and information of '1' or '0' is recorded. The metal layer 160 is made of gold.

Therefore, the cantilever of the present invention can be stably operated by using the voltage regulation method rather than the current regulation method, and the sensitivity of the drain region is very high because the amount of charge in the local region is very small.

Although the present invention has been shown and described with reference to the preferred embodiments as described above, it is not limited to the above embodiments and those skilled in the art without departing from the spirit of the present invention. Various changes and modifications will be possible.

Therefore, the read / write atomic microscope cantilever of the present invention has an effect that the effective channel length is reduced to 100 nm or less and the sensitivity is also increased by embedding a MOSFET in the nuclear microscope cantilever, thereby improving the reading function and stably writing function. There is.

Claims (4)

A cantilever support unit in which a metal layer, a first silicon layer, an oxide film, and a second silicon layer are sequentially stacked; A cantilever arm portion formed by extending only a second silicon layer of the cantilever support portion; A probe formed on a second silicon layer of the cantilever arm portion; A channel formed at the bottom of the probe; Sources / drains formed on both sides spaced apart from the center of the probe by a predetermined distance; And A gate formed between the source / drain Read / write nuclear microscope cantilever comprising a. The method of claim 1, And the channel is doped with p-type impurity, and the source and drain are doped with n-type impurity. The method of claim 1, Readable and writeable atomic force microscope cantilever, characterized in that the channel is less than 100nm. The method of claim 1, Readable / writeable atomic force microscope cantilever, characterized in that the metal layer is gold.

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