SCANNING PROBE MICROSCOPE

Abstract

The invention provides a scanning probe microscope capable of eliminating the influence of vibration noise and obtaining, accurately and with high resolution, surface information of a sample S. A scanning probe microscope 1 includes: a main body unit 10; a control unit 30; and a wireless stand 60 that is connected to the control unit 30 through a power supply signal cable 42 and includes a power supplying coil 63 and a transmission and reception unit 64. The main body unit 10 includes: a cantilever 21 with a probe 21a; a sensor 23 for detecting displacement of the cantilever 21; an XYZ drive mechanism 25 that is controlled by the control unit 30 to move the cantilever 21 or the sample S; a vibration isolation mechanism 12; a power receiving coil 13; and a transmission and reception unit 14 for communicating with the transmission and reception unit 64.

Claims

1. A scanning probe microscope, comprising: a cantilever having a probe in a free end portion; a sensor that can detect a displacement of the free end portion of said cantilever; an XYZ drive mechanism that can move said cantilever or a sample in the XYZ directions; a main body unit having a vibration isolation mechanism that can remove vibrations; and a control unit that can control said XYZ drive mechanism, and at the same time can acquire surface information of a measured area of said sample, characterized by further comprising: a wireless stand having a power supplying coil and a transmission and reception unit on the stand side; and a power supply signal cable for connecting said wireless stand to said control unit, wherein said main body unit comprises: a high voltage generating circuit that can generate a high voltage signal for driving said XYZ drive mechanism; a power receiving coil to which power can be supplied from said power supplying coil; and a transmission and reception unit on the main body side that can communicate with said transmission and reception unit on the stand side.

2. The scanning probe microscope according to claim 1, characterized in that said control unit turns off said power supplying coil unless a signal is received from said transmission and reception unit on the main body unit side.

3. The scanning probe microscope according to claim 1, characterized by further comprising an indicator lamp or a display that can display the state of the power supply between said power supplying coil and said power receiving coil.

4. The scanning probe microscope according to claim 1, characterized in that said XYZ drive mechanism is a piezoelectric element.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0028] FIG. 1 is a perspective diagram showing an atomic force microscope according to one embodiment of the present invention;

[0029] FIG. 2 is a side diagram showing the SPM main body unit and the wireless stand in FIG. 1;

[0030] FIG. 3 is a schematic diagram showing the internal configuration of the atomic force microscope in FIG. 1;

[0031] FIG. 4 is a perspective diagram showing a conventional atomic force microscope (AFM); and

[0032] FIG. 5 is a schematic diagram showing the internal configuration of the atomic force microscope in FIG. 4.

DESCRIPTION OF EMBODIMENTS

[0033] In the following, the embodiments of the present invention are described in reference to the drawings. Here, the present invention is not limited to the below-described embodiments, and needless to say, the invention includes various modifications as long as the gist of the present invention is not deviated from.

[0034] FIG. 1 is a perspective diagram showing the configuration of the entirety of the atomic force microscope according to one embodiment of the present invention. FIG. 2 is a side diagram showing the SPM main body unit and the wireless stand portion in FIG. 1. In addition, FIG. 3 is a schematic diagram showing the internal configuration of the atomic force microscope in FIG. 1. Here, the same symbols are attached to the same components as in the atomic force microscope (AFM) 101.

[0035] An atomic force microscope (AFM) 1 is provided with an SPM main body unit 10, a control unit 30 for controlling the entirety of the SPM main body unit 10, a wireless stand 60, a computer 50, a power supply signal cable 42 that connects the wireless stand 60 to the control unit 30, and a signal cable 55 that connects the control unit 30 to the computer 50.

[0036] The SPM main body unit 10 is provided with a housing 11 in approximately rectangular parallelepiped form and a vibration isolation table (vibration isolation mechanism) 12 in approximately rectangular parallelepiped form that is formed in the lower portion of the housing 11 so as to be placed between the housing 11 and the floor or the like.

[0037] The inside of the housing 11 is provided with: a cantilever holder 22 for supporting a cantilever 21; a light source unit 24 for emitting a laser beam; a displacement measurement unit (sensor) 23 for measuring the displacement of the cantilever 21; a sample placing table 25 on which a sample S is to be placed; a power receiving coil 13; an optical module (a transmission and reception unit on the main body side) 14; a high voltage generating circuit 15 for supplying a high voltage to a control circuit 16; and a control circuit 16 for controlling the light source unit 24 and the sample placing table 25.

[0038] The power receiving coil 13 and the optical module 14 are provided in the housing 11 on the rear surface side and connected with the below-described wireless stand 60 through a wireless structure. The optical module 14 is made of a reception unit 14a that optically receives a control signal from a transmission unit 64b and a transmission unit 14b that optically transmits a power supply state signal or a displacement signal to a reception unit 64a, and the power is supplied to the power receiving coil 13 from the power supplying coil 63.

[0039] The control circuit 16 controls the light source unit 24 and the sample placing table 25 on the basis of the control signal that has been optically received by the reception unit 14a, and after that acquires a displacement signal from a photodiode 23a so as to optically transmit a displacement signal from the transmission unit 14b, and at the same time determines the amplitude of the voltage of the power receiving coil 13 in order to control the optical transmission of a power supply state signal from the transmission unit 14b. That is to say, a high speed analog signal that exceeds the speed of wireless communication is processed in the control circuit 16 in the SPM main body unit 10.

[0040] The sample placing table 25 is attached in proximity to the center portion of the housing 11 and provided with a placement surface 25a in circular form having a diameter of 15 mm as viewed from the top, for example, and a piezoelectric element (XYZ drive mechanism) 25b attached in the lower portion of the placement surface 25a. Thus, the placement surface 25a is movable in the X direction, the Y direction and the Z direction, respectively, relative to the housing 11 by means of the piezoelectric element 25b. As a result, an operator can place a sample S on the placement surface 25a, and at the same time input a drive signal (high voltage signal of which the amplitude is approximately 200V) to the piezoelectric element 25b from the control unit 16 so that the placement surface 25a can be moved in the X direction, the Y direction and the Z direction relative to the housing 11, and thus, the initial location of the surface of the sample S can be adjusted before measurement. Furthermore, a drive signal can be inputted to the piezoelectric element 25b from the control unit 16 so that the measurement points on the surface of the sample S can be scanned in the X direction, the Y direction and the Z direction during the measurement process.

[0041] The wireless stand 60 is provided with a housing unit 61 made of an upper housing portion 61a and a lower housing portion 61b. The front surface in the upper housing portion 61a is provided with a power supplying coil 63 for supplying power to the power receiving coil 13 and an optical module transmission and reception unit on the stand side) 64. In addition, the upper housing portion 61a is movable in the upward and downward directions relative to the lower housing portion 61b so that an operator can adjust the height.

[0042] The optical module (a transmission and reception unit on the stand side) 64 is made of a transmission unit 64b for optically transmitting a control signal to the reception unit 14a and a reception unit 64a for optically receiving a displacement signal or a power supply state signal from the transmission unit 14b.

[0043] Here, the power transmission between the power supplying coil 63 and the power supplying coil 13 may be carried out in accordance with an electromagnetic induction system or a magnetic resonant system. In the case where the housing 11 is used within a thermostatic chamber, a hole through which the front portion of the upper housing unit 61a can be inserted may be provided in a wall of the thermostatic chamber, or the shape of the wireless stand 60 may be changed in accordance with the location of the hole for the conventional high voltage cable 141 or the power supply signal cable 42 that are created in a wall of the thermostatic chamber.

[0044] The control unit 30 is provided with a housing 31 in approximately rectangular parallelepiped form, a power supply start switch (not shown) and a state of power supply indicator lamp (not shown), and the inside of the housing 31 is provided with a CPU 32 and a memory (storage unit) 33. In addition, for explanation, the processing functions of the CPU are divided into blocks of an input information acquisition unit 32a for acquiring input information from the below-described input information outputting unit 51a via a signal cable 55 or input information from the power supply start switch, a control signal outputting unit 32b for outputting a control signal to the transmission unit 64b via a power supply signal cable 42, a power supply coil control unit 32c for outputting a control signal to the power supplying coil 63 via a power source signal cable 42, a signal acquisition unit 32d for acquiring a displacement signal or a state of power supply signal from the reception unit 64a via a power supply signal cable 42, an information outputting unit 32e for outputting the surface shape (surface information) of the measured area of the sample S to the below-described information acquisition unit 51b via a signal cable 55, and a state of power supply indication control unit 32f for displaying the state of power supply on a state of power supply indicator lamp (not shown).

[0045] The state of power supply indication control unit 32f controls the indicator lamp so as to indicate the state of power supply at the time on the basis of the state of power supply or controls the power supplying coil control unit 32c so as to output a control signal.

[0046] For example, the state of power supply indication control unit 32f determines that the power supply system is defective unless an operation normal signal is received in response to the state of power supply at predetermined intervals and outputs a control signal that turns off the power supplying coil 63 to the power supplying coil control unit 32c. As a result, such an accident that the power supply is maintained to a foreign substance other than the power receiving coil 13, which generates heat, can be prevented.

[0047] Meanwhile, the state of power supply indication control unit 32f turns on the state of power supply indicator lamp that indicates a normal state in the case where an operation normal signal is received in response to the state of power supply. At this time, a green light is turned on in the case where the mutual positional relationship is optimal judging from the state of power supply, a yellow light is turned on in the case where the positional relationship is slightly less than optimal, and a red light is turned on in the case where the positional relationship is not optimal. As a result, the operator is to adjust the positional shift.

[0048] The computer 50 is provided with a CPU 51, a display device 53 and an input device 54. In addition, for explanation, the processing functions of the CPU 51 are divided into blocks of an input information outputting unit 51a for outputting the input information that has been inputted through the input device 54 to the input information acquisition unit 32a via a signal cable 55, an information acquisition unit 51b for acquiring the surface shape (surface information) of the measured area of the sample S from the information outputting unit 32e via a signal cable 55, and a sample information display control unit 51c for displaying the surface shape (surface information) of the measured area of the sample S on the display device 53.

[0049] As described above, in the scanning probe microscope 1 according to the present invention, the SPM main body unit 10 does not need a cable for external connection, and therefore, no vibrations enter the SPM main body 10 through a cable. In addition, the handling of the SPM main body 10 is easy because no cables are connected to the SPM main body unit 10.

[0050] After the wireless stand 60 has been arranged, the power supply start switch is pressed on the power supplying coil 63 side, for example, in order to start the power supply from that point in time. In the case where an operation normal signal is not received from the power receiving coil 13 side within a certain period of time, however, it is determined that the power supply system is defective and the power supplying coil 63 is turned off. In addition, an operation normal signal is monitored at certain intervals even while the power is being supplied, and the power supplying coil 63 is turned off in the case where the voltage on the power receiving coil 13 side is interrupted due to a shift in the positional relationship.

Other Embodiments

[0051] (1) Though the above-described atomic force microscope 1 has a configuration where the sample placing table 25 is movable in the X direction, the Y direction and the Z direction, such a configuration that the cantilever holder is movable in the X direction, the Y direction and the Z direction may be substituted.

[0052] (2) Though the above-described atomic force microscope 1 has a configuration where the bending (displacement) of the cantilever 21 is detected by using an optical lever type optical detection device, a configuration for detecting the bending of the cantilever may be provided by using other methods.

[0053] (3) Though the above-described atomic force microscope 1 has a configuration where optical communication is achieved by means of the optical modules 14 and 64, a configuration may be provided where other methods such as transmission through radio waves are used for communication. In the case of transmission through radio waves, the points at which the antennae in the SPM main body unit and the antennae in the wireless stand are positioned in such a manner as to make communication possible.

[0054] (4) Though the above-described atomic force microscope 1 has a configuration where the state of power supply indicator lamp indicates the state of power supply, a configuration may be provided where the state of power supply is displayed on a display device of the computer or on the state of power supply indicator lamp provided in the wireless stand.

[0055] (5) Though the above-described atomic force microscope 1 has a configuration where the power receiving coil 13 and the optical module 14 are provided in the housing 11 on the rear surface side, and the power supplying coil 63 and the optical module 64 are provided in the upper housing unit 61a on the front surface side, a configuration may be provided where the power receiving coil and the optical module are provided inside the housing on the bottom side, and the power supplying coil and the optical module are provided inside the housing on the top side. In addition, a configuration may be provided where a wall that surrounds the optical path or the entirety of the coil is formed between the optical modules 14 and 64 in order to prevent the optical signal from cross-talking with the ambient light.

INDUSTRIAL APPLICABILITY

[0056] The present invention can be used for scanning probe microscopes that are appropriate for the observation of the surface of a sample.

REFERENCE SIGNS LIST

[0057] 1 atomic force microscope (scanning probe microscope)

[0058] 10 SPM main body unit

[0059] 12 vibration isolation table (vibration isolation mechanism)

[0060] 13 power receiving coil

[0061] 14 optical module (a transmission and reception unit on the main body unit side)

[0062] 15 high voltage generating circuit

[0063] 21 cantilever

[0064] 21a probe

[0065] 23 displacement measurement unit (sensor)

[0066] 25 piezoelectric element (XYZ drive mechanism)

[0067] 30 control unit

[0068] 42 power supply signal cable

[0069] 60 wireless stand

[0070] 63 power supplying coil

[0071] 64 optical module (transmission and reception unit on the stand side)