Abstract:
A signal having a resonant frequency of a cantilever is output by a first oscillator, and supplied to a vibrating element and a control unit to oscillate a probe. A low frequency signal having a large amplitude is output by a second oscillator and supplied to a piezoelectric scanning apparatus. The probe is periodically and relatively moved with respect to the sample between a position where the sample surface is penetrated by the probe and another position where the probe does not penetrate the sample surface and is outside the range of atomic forces caused by the sample. During this movement, the probe movement may be analyzed to obtain a plurality of physical characteristics about the sample, e.g., hardness information of the sample, surface shape information, information related to an adsorption layer of the sample, and information related to physical qualities (for example, electromagnetic field, adsorption force, surface reaction force, electric double layer force in fluid) irradiated from the sample surface along a depth direction.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a three-dimensional scanning probe microscope, and more specifically, is directed to such a three-dimensional scanning probe microscope capable of acquiring a plurality of types of physical information of a sample during a single scanning operation or single pass. 
     As a method for observing a shape of a sample surface and a physical amount characteristic of the sample surface using a conventional scanning probe microscope, an observation method is mainly subdivided into a method for observing a sample while a probe is brought in contact with the sample, and another method for observing a sample while a probe is not brought in contact with the sample. 
     When a sample is observed by way of the former method, for instance, concave/convex images of a surface of the sample and friction images thereof can be separately observed. On the other hand, when a sample is observed by way of the latter method, physical information emitted from a surface of the sample, for example, a magnetic distribution image and an electrostatic distribution image of the sample can be observed. 
     In the above-described observation methods, the sample surface is scanned in a two-dimensional manner by the probe so as to be observed, while the probe is brought in contact with the sample surface, or is separated from the sample surface by a predetermined distance. As a result, data which is acquired during a single observation operation merely corresponds to a single physical amount contained in a sample. These observation methods are not especially designed to be capable of acquiring a plurality of physical amounts during a single observation operation. Also, in the conventional observation methods, for instance, in such a case that a magnetic distribution image of a sample is observed, although the two-dimensional magnetic distribution image of the sample where the probe is at a position separated from this sample by a preselected distance can be observed, there is a problem. That is, a three-dimensional magnetic distribution image of the sample cannot be observed. This three-dimensional magnetic distribution image is produced by adding a magnetic distribution of a height direction of the sample to this two-dimensional magnetic distribution image. 
     The present invention has been made in view of the shortcoming of the above-described conventional techniques, and provides a three-dimensional scanning probe microscope capable of observing a plurality of physical amounts of a sample while an observation is carried out in one pass. Another object of the present invention is to provide a three-dimensional scanning probe microscope capable of acquiring a physical characteristic of a sample in a three-dimensional manner. 
     SUMMARY OF THE INVENTION 
     To achieve the above-explained objects, a three-dimensional scanning prove microscope, according to a first feature of the present invention, is featured by being a three-dimensional scanning probe microscope equipped with a probe capable of performing relative scanning operations along an x direction and a y direction in parallel to a surface of a sample, and also a moving operation along a z direction perpendicular to the sample surface with respect to the sample surface, wherein the probe is moved along the z direction at a second frequency in such an amplitude at least defined from a first position where the sample surface is depressed by the probe up to a second position where the probe is not influenced by atomic force with respect to the sample surface so that a plurality of data characteristics can be acquired during the movement of the probe. Also, a second feature of the present invention is featured by that the probe is vibrated at a first frequency (first frequency&gt;second frequency) which is resonated, or forcibly vibrated with the probe. 
     In accordance with the present invention, since the probe can be periodically and relatively moved from a position where the probe is separated from the sample up to another position where the probe is depressed into this sample with respect to the sample, plural sorts of physical information of the sample can be acquired while the probe is moved within 1 time period. Also, since the information acquired within this 1 time period can be used as the information about one pixel, this scanning operation by the probe is extended over the entire check region of the sample. As a consequence, the plural sorts of physical information of this sample can be acquired during one scanning operation (one pass). Also, since the resultant plural sorts of physical information are acquired from the same point of the sample, these plural sorts of physical information own relative relations with each other, which may contain valuable information. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic block diagram for indicating an arrangement of an embodiment of the present invention. 
     FIGS. 2A-2D are waveforms charts of signals of major portions in FIG.  1 . 
     FIG. 3A is a waveform chart of a signal outputted from a second oscillator of FIG. 1, and 
     FIG. 3B is a diagram for representing a relationship between a sample and a probe operated in response to this signal. 
     FIG. 4 is a diagram for representing a relationship between the probe and the sample, and a relationship between the probe and data acquired from this probe. 
     FIG. 5 is a block diagram for representing one example of functions of a control unit shown in FIG.  1 . 
     FIG. 6 is a block diagram for showing an example of a circuit for measuring a dynamic viscous/elastic characteristic. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the attached drawings, the present invention will be described in detail. FIG. 1 is a schematic block diagram for indicating an arrangement of an embodiment of the present invention. 
     In this drawing, reference numeral  1  shows a piezoelectric scanning apparatus in which an electrode  1   a  used for a z-fine moving operation, 4-split electrodes  1   b ,  1   c ,  1   d ,  1   e  ( 1   d  and  1   e  are not shown) for an x-scanning operation and a y-scanning operation are provided on a cylindrical surface of a cylindrical piezoelectric element. A sample  2  to be monitored is mounted on an upper surface of this piezoelectric scanning apparatus  1 . Above this sample  2 , a cantilever  3  having a probe located opposite to the sample  2  is provided. A vibrating element  4  is fixed on one end of the cantilever  3 , and this vibrating element  4  causes the cantilever  3  to be resonated upon receipt of a signal having a first frequency outputted from a first oscillator  5 . As shown in FIG. 2A, a signal having an amplitude A1 (1 nm≦A1≦500 nm) and a frequency f1 equal to a resonant frequency of the cantilever  3  is outputted from this first oscillator  5 . It should be understood that as this frequency f1, such a frequency may be employed by which the cantilever  3  is forcibly vibrated. 
     A distortion amount of the above-described cantilever  3  is detected by measuring an incident position of laser light  7  outputted from a laser generator  6  by a position detector  8 . The position detector  8  is constructed by, for instance, a four-segment optical detecting electrodes. This position detector  8  is positioned in such a manner that when the distortion amount of the cantilever  3  becomes 0, the spot of the laser light  7  is located at a center of these four-segment electrodes. As a result, when distortion occurs in the cantilever  3 , the spot of the laser light  7  is moved on the four-segment electrodes, and a difference is produced in voltages outputted by the four-segment electrodes. This voltage difference is amplified by an amplifier  9  to become a signal “a”. The signal “a ” is inputted to a control unit  10 . 
     As shown in FIG. 2B, the second oscillator  11  outputs such a signal having an amplitude A0 (10 nm≦A0≦3,000 nm) and a frequency f2 (f2&lt;f1). The signal outputted from this second oscillator  11  is added by an adder  13  to a feedback signal outputted from a z-servo system  12 . The added signal is applied to the z-fine-moving electrode  1   a  of the piezoelectric scanning apparatus  1 . 
     An x, y scanning unit  21  produces an x scanning signal and a y scanning signal. The x scanning signal is applied to the electrodes  1   b  and  1   d  for the x scanning operation, whereas the y scanning signal is applied to the electrodes  1   c  and  1   e  for the y scanning operation. Also, these x and y scanning signals are sent to a computer  39 . Reference numerals  31  to  34  show A/D converters for converting the input data into digital signals. Reference numerals  35  to  38  indicate memories for storing thereinto the digital data outputted from these A/D converters  31  to  34 , and are, for example, frame memories. A calculating/image displaying computer  39  selectively reads the digital data stored in the memories  35  to  38 , and calculates these digital data to be converted into image display data. Then, the calculating/image displaying computer  39  sends out the image display data to an image display device  22 . The image display device  22  displays a physical characteristic of the sample  2 . 
     Next, the operations of the three-dimensional scanning probe microscope shown in FIG. 1 will now be summarized with reference to FIGS. 3A and 3B, while paying an attention to a distance between the sample  2  and the above-described probe. In FIGS. 3A and 3B, the same reference numerals shown in FIG. 1 indicate the same, or similar elements. FIG. 3A shows 1 time period “T” of a signal outputted from the second oscillator  11 . This signal may be expressed by, for instance, A0 cos 2 π ft (not the symbol “f” is a frequency, and symbol “t” denotes time) equal to a cosine function. Alternatively, this signal may be expressed by a signal having another waveform. 
     At a time instant {circle around ( 1 )} when the amplitude of this signal is maximum, as represented by {circle around ( 1 )} in FIG. 3B, the sample  2  is located at the lowermost position, and the distance between the probe and the sample  2  becomes maximum. As previously explained, since the amplitude A0 is sufficiently large, at this time, the probe is located at a reference position sufficiently separated from the sample surface. At a time instant {circle around ( 2 )} of this signal, the sample  2  is lifted up to such a position as represented as {circle around ( 2 )} of FIG. 3B, and thus the probe is made in contact with the surface of the sample  2 . At a time instant {circle around ( 3 )} of the signal, the sample  2  is located at the uppermost position where the probe is depressed into the deepmost position in this sample  2 . At this time, the cantilever  3  is bent to one side. 
     At a time instant {circle around ( 4 )} of this signal, the sample  2  descends up to the substantially same height as that of the above-described time instant {circle around ( 2 )}. At this time, the depression force by the probe against the sample  2  becomes substantially zero. At time instants {circle around ( 4 )} to {circle around ( 5 )} of the signal, since the sample  2  further descends, the probe is tried to be separated from the sample  2 . However, due to the adsorption force of the sample  2 , the probe is set under such a condition that this probe cannot be separated from the sample  2 . The cantilever  3  is bent to the other side. Then, at a time instant {circle around ( 5 )}, the probe is separated from the sample  2  by releasing the adsorption force of the sample  2 . At a time instant {circle around ( 6 )}, the probe is returned to the original reference position. At the time instant {circle around ( 1 )} of the end of the above-described 1 time period T, the sample  2  is returned to the original position (height). 
     As indicated in FIG. 3A, a time period defined between the time instant {circle around ( 1 )} and the time instant {circle around ( 2 )} may be referred to as a “non-contact time period”; another time period defined between the time instant {circle around ( 2 )} and the time instant {circle around ( 5 )} may be referred to as a “contact time period”, and another time period defined between the time instant {circle around ( 6 )} and the time instant {circle around ( 1 )} may be referred to as a “non-contact time period”. 
     When the above-described operation for 1 time period T is accomplished, the probe can acquire the data for 1 pixel among the detected image information of the sample  2  displayed on the image display device  22 . 
     A waveform of FIG. 2C indicates a waveform of an output signal (waveform at point A) from the position detector  8  of FIG.  1 . Numerals surrounded by circles shown in FIG. 2C correspond to numerals surrounded by circles indicated in FIGS. 3A and 3B. FIG. 2D denotes a relative position of the cantilever  3  in such a case that the sample  2  is fixed at a position of a point “0”. 
     As shown in FIG.  2 C and FIG. 2D, during a time period defined between a time instant {circle around ( 1 )} and a time instant {circle around ( 2 )}, in response to the signal derived from the first oscillator  5 , while the probe is vibrated at the resonant frequency of the cantilever  3 , this probe approaches to the surface of the sample  2 . At this time, when a certain physical amount (for example, magnetic field, electric field, adsorption force, surface reacted force, electric double layer force in fluid, etc.) is produced from the surface of the sample  2 , this probe is influenced by this physical amount, so that a phase shift occurs in the phases of the resonant frequency. When this phase shift is detected, the physical amount derived from the surface of the sample  2  can be detected as a function of a distance measured from the sample surface. 
     Next, in another time period defined between a time instant {circle around ( 2 )} and a time instant {circle around ( 3 )}, since the probe is depressed into the sample  2 , hardness information of the sample  2  can be acquired by calculating an inclination of a waveform shown in FIG. 2C during the time period defined between the time instants {circle around ( 2 )} and {circle around ( 3 )}. Next, the feedback control by the z-servo system  12  shown in FIG. 1 is performed in such a manner that the depression distance “hmax” of the probe  2  into the sample  2  at the time instant {circle around ( 3 )} becomes constant, so that the shape information of the surface of this sample  2  can be acquired from the information of this probe. 
     Furthermore, since a waveform during a time period defined between a time instant {circle around ( 4 )} and a time instant {circle around ( 5 )} is produced by such a fact that the sample  2  absorbs the probe, the viscous information related to the adsorption layer of this sample  2  can be acquired from the inclination of this waveform. Also, at a time instant {circle around ( 6 )}, namely when the probe is separated from the surface of the sample  2  and thereafter is returned to the reference position thereof, the information related to the adsorption force of the above-described adsorption layer can be acquired. FIG. 4 illustrates that the above-explained physical information which can be acquired by the probe during 1 pixel period is indicated at the respective numerical points. 
     As previously described, according to the present invention, more than 5 types of these physical characteristics of this sample  2  can be acquired by merely scanning the probe only one time with respect to the sample  2 . Also, since the above-described plural types of information are not separately acquired, but can be obtained from the same place at the same time, this acquired information may give rise to very important physical characteristic of the sample  2 . 
     It should be noted that the time instants indicated in FIG. 2D except the time instant “τn” are indicated while the time instant “t0” at the maximum point of the output signal (FIG. 2B) derived from the second oscillator  11  is set as a reference (namely, t0=0); a time instant “tc” indicates time defined until the probe is made in contact with the sample  2 ; a time instant “Tc” indicates time defined until the probe is depressed into the sample  2  and then reaches the deepmost point; a time instant “Tr” indicates time defined until the probe is separated from the sample  2 ; and also a time instant “tn” shows time 0≦tn&lt;tc. The time instant “τn” denotes time 0&lt;τn&lt;(Tc−tc). The above-explained various time will be used in the below-mentioned description. 
     Referring now to FIG.  1  and FIG. 5, an arrangement and operations of an apparatus, according to an embodiment, capable of acquiring the above-explained physical information will be described. FIG. 5 is a block diagram for indicating a function of a control unit  10  shown in FIG.  1 . 
     When a signal “a” shown in FIG. 2C corresponding to the output signal of the position detector  8  is entered into the control unit  10 , this signal “a” is inputted into a low-pass filter  41 , a root-mean-square detector  42 , a phase comparator  43 , and a maximum/minimum value detecting circuit  44 . 
     The low-pass filter  41  extracts a low frequency component of the signal “a” in order that a frequency component f1 of this signal is eliminated, and then supplies the filtered signal to a sample/hold circuit  48 . When the root-mean-squared calculation value of the signal “a” becomes lower than, or equal to a threshold value, namely a very small amplitude, the root-mean-square detector  42  triggers a trigger signal generator  46 . This trigger signal generator  46  outputs a time signal of the above-described time tc. The timing signal of this time tc is supplied to a second sampling pulse generator  54  so as to initiate this second sampling pulse generator  54 . When the second sampling pulse generator  54  is initiated, the above-described time signals τ1 to τn are outputted. 
     The phase comparator  43  compares the phase of the signal “a” with the phase of the output signal (FIG. 2A) derived from the first oscillator  5 , and then outputs a phase difference signal to the sample/hold circuit  45   a  to  45   d . The maximum/minimum value detecting circuit  44  detects such timing when the signal “a” becomes maximum and minimum, and then outputs the detected timing to the trigger signal generator  47 . The trigger signal generator  47  supplies, for instance, a clear rectangular trigger signal to the sample/hold circuit  49  at such timing Tr when the maximum value of the signal “a” is detected, and supplies a trigger signal to the sample/hold circuit  50  at such timing Tc when the minimum value is detected. 
     On the other hand, the signal (FIG. 2B) outputted from the second oscillator  11  is processed in a maximum value detecting circuit  51  in such a manner that timing at which this signal becomes maximum is detected. At this detection time instant t0, the trigger signal generator  52  outputs a trigger signal. This trigger signal triggers a first sampling pulse generator  53 , and also resets the sample/hold circuits  45   a  to  45   d ,  55   a  to  55   d , and  48  to  50 . 
     The first sampling pulse generator  53  outputs time signals t1 to tn (tn&lt;tc) having a preselected time interval in synchronism with this trigger signal. When these time signals t1 to tn are entered into the sample/hold circuits  45   a  to  45   d , these sample/hold circuits  45   a  to  45   d  sample/hold the phase difference signal outputted from the phase comparator  43  at the respective timing thereof. The sample/hold circuits  45   a  to  45   d  output sampled/held phase difference signals φ1 to φn. 
     On the other hand, the second sampling pulse generator  54  outputs time signals τ1 to τn (0&lt;τ1, τn&lt;(Tc−tc)) having a preselected time interval in synchronism with this time signal tc. When these time signals τ1 to τn are entered into the sample/hold circuits  55   a  to  55   d , these sample/hold circuits  55   a  to  55   d  sample/hold the low frequency signal outputted from the low-pass filter  41  at the respective timing thereof. The sample/hold circuits  55   a  to  55   d  output sampled/held values h1 to hn of the signal “a” during the time period defined between the time instant {circle around ( 2 )} and the time instant {circle around ( 3 )}. 
     A first arithmetic circuit  61  subtracts the value held by the sample/hold circuit  48  from the value held by the sample/hold circuit  49  to thereby produce the above-explained value hrmax. Also, a second arithmetic circuit  62  subtracts the value held by the sample/hold circuit  48  from the value held by the sample/hold circuit  50  to thereby produce the above-described value hmax. It should be noted that since a value obtained at a time instant {circle around ( 4 )} is substantially equal to a value obtained at a time instant {circle around ( 2 )}, the value obtained at the time instant {circle around ( 2 )} may be substituted by the value obtained at the time instant {circle around ( 4 )}. 
     Next, the physical amount of the sample  2  acquired in accordance with this embodiment will now be explained in detail. 
     In accordance with this embodiment, the below-mentioned data (1) to (4) may be acquired every pixel (xi, yi) during the above-described 1 time period (1 pixel data acquisition time) T: 
     (1) hmaxxiyi: a signal of the cantilever  3  for a pixel (xi, yi) at a time instant Tc. 
     (2) hrmaxxiyi: a signal of the cantilever  3  for the pixel (xi, yi) at a time instant Tr. 
     (3) φxiyi (t1) to φxiyi (tn): a phase difference between an output signal of the cantilever  3  and an output signal of the first oscillator  5  for the pixel (xi, yi) at a time instant ti. 
     (4) hxiyi (tc+τ1) to hxiyi (tc+τn): a signal of the cantilever  3  for the pixel (xi, yi) at a time instant tc+τi. 
     The data hmaxxiyi of the above item (1) is supplied to the z-servo system  12  of FIG.  1 . The z-servo system  12  supplies a feedback signal produced based on this data hmaxxiyi to the z-fine-moving electrode  1   a  of the piezoelectric scanning apparatus  1  so as to control that the distance between the probe and the sample  2  becomes constant. At this time, the control values of the z-servo system  12  are converted into digital values by the A/D converter  34  every pixel. These digital control values are stored in the memory  38 . When the signals stored in the memory  38  are displayed on the image display device  22 , the surface shape of the sample  2  can be displayed. 
     Next, the data hrmaxxiyi of the above-described item (2) are converted into digital values by the A/D converter  31 , and these digital values are stored into the memory  35 . When the digital signals stored in the memory  35  are displayed on the image display device  22 , an adsorption distribution image of the adsorption layer of the sample  2  can be obtained. 
     Next, the data φxiyi (ti) to φxiyi (tn) of the above-described item (3) are converted into digital values by the A/D converter  32 , and these digital data are stored into the memory  36 . These data φxiyi (ti) to φxiyi (tn) are processed by the calculating/image displaying computer  39  in accordance with the following data converting process operation. 
     Assuming now that the resonant frequency of the cantilever  3  is “fr”, the below-mentioned formula may be satisfied: 
     Formula 1 
     
       
         2π fr=ωr={square root over (k/Meff)}   
       
     
     K: spring constant of cantilever 
     Meff: effective mass of cantilever. 
     At this time, when the cantilever  3  vibrated at the resonant frequency is positioned close to the surface of the sample  2 , this resonant frequency is influenced by force F of the surface of the sample  2 , so that this resonant frequency “ωr” is changed into ωr′. This resonant frequency ωr′ may be expressed by the below-mentioned formula. It should be noted that as this force F, there are magnetic force, electrostatic force, and Van der Waals force. 
     Formula 2 
     
       
         Sin ω r′t =Sin(ω rt−φi )=Sin{square root over (( k−∂F/∂hi +L )/ Meff +L )}·t ωr′t=ωrt−φi={square root over (( k−∂F/∂hi +L )/ Meff +L )}·t  
       
     
     φi: phase difference between signal of cantilever  3  and output signal of first oscillator  5  at height “hi” from sample surface; 
     hi: height from sample surface 
     ∂F/∂hi: differential field at height “hi” from sample surface. 
     Accordingly, 
     
       
         ω r′= {square root over (( k−∂F/∂hi +L )/ Meff +L )} 
       
     
     As a consequence,            ∂   F       ∂   hi       =     k   -     ω                   r   ′2        Meff                              
     In the above formula, “K” and “Meff” are constant values. As a consequence, a distribution of force F at the distance hi from the surface of the sample  2  with respect to the each of the pixels (xi, yi) can be obtained from the above formula. In other words, a distribution of the formula F along a depth direction from the surface of the sample  2 , namely a distribution of the above-described magnetic force, electrostatic force, and Van der Waals force can be obtained. 
     It should be noted that the distance hi between the probe and the sample  2  at a time instant “ti” may be expressed by the below-mentioned formula: 
     
       
           hi=|A 0cos (2π tc/T )− A 0cos (2π ti/T )| 
       
     
     where symbol “tc” represents a time instant when the probe is made in contact with the sample surface, and is defined by ti&lt;tc. 
     Subsequently, the data hxiyi (tc+τ1) to hxiyi (tc+τn) of the above-described item (4) are converted into digital values by the A/D converter  33 , and then the digital values are stored into the memory  37 . As to these data hxiyi (tc+τ1) to hxiyi (tc+τn), the calculating/image display computer  39  executes the below-mentioned data converting process operation. 
     Considering now a time range during which the probe is depressed into the sample  2 , namely (tc+τ1) to (tc+τn). As a result, a depression distance hpi (tc+τi) of the probe at the time instant (tc+τi) is defined by the following formula: 
     
       
           hpi ( tc+τn )= A 0cos (2π tc/T )= A 0cos {2π( tc/τi )/ T}   
       
     
     As a consequence, force Fpi by the probe which depresses the surface of the sample  2  at the item instant (tc+τi) is given as follows, assuming now that the spring constant of the cantilever  3  is “K”: 
     
       
           Fpi=K·hpi ( tc+τi ).  
       
     
     This force Fpi can be balanced with the reaction force produced from the surface of the sample  2 . As a result, assuming now that a localized spring force of the sample surface is “ks”, the actual move amount of the probe is given as follows, since the signal from the cantilever  3  is equal to hxiyi (tc+τi): 
     
       
           Fpi=K·hpi ( tc+τi )= K·hxiyi ( tc+τi )+ Ks ( tc+τi )· hxiyi ( tc+τi )  
       
     
     Accordingly, 
     
       
           ks ( tc+τi )= K ( hpi ( tc+τi )− hxiyi ( tc+τi ))/ hxiyi ( tc+τi )  
       
     
     The localized spring constant “ks” of the sample surface is calculated in the above manner, and when these data are displayed on the image display device  22 , the hardness distribution of the surface of the sample  2  can be acquired. 
     Also, a dynamic viscous/elastic characteristic of the sample  2  can be acquired as follows. That is, the probe is made in contact with the sample surface, and while the cantilever  3  is fine-vibrated during a certain section (namely, from time instant {circle around ( 2 )} to time instant {circle around ( 4 )} in FIG. 2C) in the sample, the phases of the vibrations of the cantilever and the phases of the oscillator  5  are measured in the time sequences τ1′ to τn′. Then, phase differences φ1′ to φn′ measured to acquire this dynamic viscous/elastic characteristic of the sample  2 . As readily a circuit for measuring this dynamic viscous/elastic characteristic, a circuit shown in FIG. 6 is merely added to the circuit indicated in FIG.  5 . This measuring circuit may be arranged by a sampling pulse generator  71  for generating sampling pulses τ1′, τ2′, τ3′ and τn′; sample/hold circuits  72  to  75  for sampling/holding the output signal from the phase comparator  43  at the respective timing of these sampling pulses τ1′, τ2′, τ3′ and τn′; an A/D converter  76  for A/D-converting the phase differences φ1′ to φn′ corresponding to the outputs from these·sample/hold circuits  72  to  75 , namely for A/D-converting the viscous/elastic data; and further a memory  77 . The data stored in this memory  77  are then supplied to the computer  39 . In accordance with this circuit, it is possible to acquire viscous data φixiyi (τi′) at a depth point hi′ of a certain point (xi, yi) on the sample surface. 
     The above-described embodiment has be described based on such an apparatus that the sample  2  is mounted on the piezoelectric scanning apparatus  1 , and this sample  2  is moved along the upper/lower directions. However, the present invention is not limited thereto, but may be modified. For example, the cantilever  3  is fixed on this piezoelectric scanning apparatus  1 , and while the cantilever  3  may be scanned along the x/y directions, this cantilever  3  may be moved in the fine mode along the z direction. 
     As is readily apparent from the above-described explanations, according to the present invention, the probe is moved along the z direction at the first frequency with such an amplitude defined from the position where at least the sample is depressed by the probe up to the position where the probe does not receive the atom reacted force with respect to the sample surface, and the data are acquired while this probe is moved. As a consequence, there is such an effect that the distributions of the physical amounts (for example, magnetic field, electric field, atom reacted force, etc.) distributed from this sample surface along the depth direction can be monitored in the three-dimensional manner. 
     Also, there is another effect that plural sorts of data involved by one point of the sample can be simultaneously acquired while the probe is reciprocated in one turn along the z direction, namely while the data of 1 pixel are acquired. Furthermore, this operation is continued over the entire observation region of the sample, so that the natures of the entire sample can be checked in the multiple aspects. There are further effects that since these plural sorts of data are acquired within 1 scanning operation, these plural sorts of data own the mutual relationships, and also the probe microscope with high operability can be provided. 
     Also, there is a further effect that as the plural sorts of data, at least two sorts of data can be acquired. Concretely speaking, there are the depth-direction distribution of the physical amount (for instance, magnetic field, electric field, atom reacted force, electric double layer force in fluid, etc.) irradiated from the sample surface; the sample hardness information; the surface shape information of the sample; and the information (for instance, viscous degree and adsorption force of adsorption layer) related to the adsorption layer of the sample.