CN105675922A - Method and system for correcting scanning range of piezoelectric ceramic tube scanner - Google Patents

Abstract

The invention discloses a method and system for correcting the scanning range of a piezoelectric ceramic tube scanner, and the method comprises the steps: selecting one scanning range correction method based on sample thickness from a calculation correction method, a blind correction method and a fitting correction method, and obtaining the relation between the actual scanning range of the piezoelectric ceramic tube scanner and the sample thickness; obtaining the actual thickness of a tested sample, and correcting the scanning range of the piezoelectric ceramic tube scanner according to the actual thickness of the tested sample and the relation between the actual scanning range and the sample thickness. According to the invention, the calculation correction method, the blind correction method and the fitting correction method are added, and the method can obtain the relation between the actual scanning range and the sample thickness, corrects the scanning range according to the actual thickness of the sample, effectively corrects the change, caused by the change of the sample thickness, of the scanning range of the piezoelectric ceramic tube scanner, and is more accurate and reliable. The method can be widely used in the technical field of microscopes.

Description

The sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner and system

Technical field

The present invention relates to microscopy field, the sweep limits bearing calibration of especially a kind of piezoelectric ceramics tube scanner and system.

Background technology

After nineteen eighty-two PSTM (STM) occurs, develop again the novel microtechnique that a series of activities principle is similar successively, mainly include atomic force microscope (AFM), cross force microscope (LFM), magnetic force microscopy (MFM), electrostatic force microscope (EFM), NFM (SNOM), piezoelectric forces microscope (PFM), scan probe acoustics microscope (SPAM) etc., it is all utilize probe that sample is scanned due to them, the interaction (interaction force etc. as between sample-probe) of detection scanning process middle probe and sample simultaneously, obtain sample relevant nature (such as pattern, frictional force, domain structure etc.), thus it is collectively referred to as scanning probe microscopy (SPM).

In order to reach nano level resolution, the three-dimensional motion that scanning probe microscopy is substantially according to piezoelectric scanner is scanned imaging. Due to piezoelectric ceramics lagging characteristics inherently, there is between its deformation quantity and driving voltage obvious non-linear relation. Driving scanning device for simple linear voltage, the sample motion of scanning device is nonlinear, therefore its scanning obtains image and can there is distortion, it is necessary to be corrected. At present, the research work for Piezoelectric scanning probe microscope system is concentrated mainly on relation and the non-linear correction method of piezoelectric ceramics deformation quantity and driving voltage, and conventional non-linear correction method has open-loop calibration method and closed loop calibration method.

Open-loop calibration method, refer to and adopt nano-grade displacement detection technique that scanning device is detected in advance, obtain the driving voltage of scanning device and the relation of sample stage displacement, in scanning device use in the future, based on the relation in advance obtained, scanning device is applied appropriate driving voltage, accurately control the displacement of sample stage and realize linear movement. Closed loop calibration method, it is simply that load onto displacement transducer in scanning device, the in real time motion of detection scanning device sample stage (being placed with standard sample on sample stage).Closed loop calibration method is similar with open-loop calibration method, simply displacement transducer is arranged in scanning device, the displacement of scanning device sample stage is detected in real time, and scanning device driving voltage is carried out real-time feedback control, thus realizing the real-time closed-loop of scanning device sample stage motion is controlled. Owing to closed loop calibration method must be integrated by displacement transducer and piezoelectric scanner, therefore at present adopt capacitance sensors or the less sensor of foil gauge equal-volume more.

At present, nano-grade displacement detection method conventional in scanner calibration includes capacitive displacement transducer method, linear variable difference transformer (LinearVariableDifferentialTransformer, LVDT) method, strain gauge method and laser interferance method, CAS Electrical Engineering Research Institute is 200310113670.6 at application number, just describes the method adopting laser interference (Michelson's interferometer) to correct piezoelectric ceramics nonlinear effect in the patent of invention of " nonlinear correction method for piezoelectric ceramic tube scanner " by name.

Piezoelectric scanner mainly includes piezo-ceramic tube type and flatbed etc., wherein, piezoelectric ceramic tube type scanner has that volume is little, simple in construction, good stability, fast response time and the advantage such as driving is easy to control, it is current resolution piezoelectric scanner type high, the most with low cost, therefore it is most widely used in scanning probe microscopy. One wall electrode is carried out four-quadrant segmentation by piezoelectric ceramics tube scanner, and is constituted 5 independent electrodes to split four electrodes obtained with inwall electrode, the motion three-dimensional to realize X-Y-Z.

Scanning probe microscopy controls piezoelectric ceramics tube scanner by voltage signal and moves in X-Y plane, probe or sample is driven to be scanned, obtain the interaction information of probe and sample room, and the change according to interaction information, control piezoelectric ceramics tube scanner and move (upper and lower telescopic moving) in Z-direction, to offset the surface undulation of sample, the interaction of probe and sample room is made to keep constant, thus obtaining the surface information such as surface topography of sample.

The scanning in X-Y plane of the piezoelectric ceramics tube scanner makes piezoelectric ceramic tube extend by voltage signal while shortening produced bending and realizing, and its sweep limits can become big because of the increase of the length (when adopting the mode of probe scanning) of the thickness of sample (when adopting the mode of Sample Scan) or probe. Current scanning probe microscopy, generally it is integrated with multiple detection technique, and probe many employings laser detection mode, detection process need the relative position keeping probe and laser detection system constant, it is relatively big that the mode adopting probe scanning implements difficulty, therefore piezoelectric ceramics tube scanner adopts Sample Scan mode mostly. Probe is as the consumable goods in scanning probe microscopy, current probe has realized generalization large-scale production substantially, its geometry concordance is fine, the length of probe is basically unchanged, and on the other hand, a lot of in the kind of actually detected middle sample, the diversity of thickness is very big, cause that the error of actual scanning scope is relatively big, as not being corrected directly affecting the accuracy of testing result according to corresponding thickness in time.

But, current piezo-ceramic tube type scanning microscope, no matter it is adopt existing open-loop calibration method or closed loop calibration method, what detected is all the motion of the motion of piezoelectric ceramics tube scanner sample stage rather than sample, the thickness of all samples is all defaulted as the thickness of standard sample, can not calibrate because of the sweep limits error caused by thickness of sample difference, not accurate enough and reliable.

Summary of the invention

For solving above-mentioned technical problem, it is an object of the invention to: provide a kind of accurately with reliably, the sweep limits bearing calibration of piezoelectric ceramics tube scanner.

Another object of the present invention is to: provide a kind of accurately with reliably, the sweep limits correction system of piezoelectric ceramics tube scanner.

The technical solution used in the present invention is:

A kind of sweep limits bearing calibration of piezoelectric ceramics tube scanner, it is characterised in that: comprise the following steps:

S1, from calculating correction method, school for the blind executes selected a kind of sweep limits bearing calibration based on thickness of sample with in fitting correction method, and the actual scanning scope of piezoelectric ceramics tube scanner and the relation of thickness of sample is obtained according to selected bearing calibration, wherein, calculate correction method according to given piezoelectric ceramics length of tube, given sample stage height and the standard sample of 1 given thickness obtain the relation of actual scanning scope and thickness of sample, school for the blind executes the relation obtaining actual scanning scope and thickness of sample according to the standard sample that two given thickness is different, fitting correction method simulates the relation of actual scanning scope and thickness of sample according to the result of the standard sample actual scanning imaging of the given thickness of a series of differences,

S2, obtain the actual (real) thickness of sample, and the sweep limits of piezoelectric ceramics tube scanner is corrected by the relation according to the actual (real) thickness of sample and actual scanning scope with thickness of sample.

Further, described calculating correction method is related to this step according to what the standard sample of given piezoelectric ceramics length of tube, given sample stage height and 1 given thickness obtained actual scanning scope and thickness of sample, itself particularly as follows:

Obtain the relational expression of actual scanning scope S and thickness of sample T according to the standard sample that given piezoelectric ceramics length of tube L, given sample stage height H and 1 given thickness are T0, the relational expression of described actual scanning scope S and thickness of sample T is:

$S=(1+\frac{2(T-T0)}{L+2H+2T0})S0,$

Wherein, S0 is the sweep limits that standard sample is demarcated.

Further, described school for the blind executes and is related to this step according to what the standard sample that two given thickness is different obtained actual scanning scope and thickness of sample, itself particularly as follows:

Actual scanning scope is performed twice at demarcation by the standard sample according to two given thickness respectively T0 and T1, then show according to the result of twice demarcation that the relational expression of actual scanning scope S and thickness of sample T, the relational expression of described actual scanning scope S and thickness of sample T are:

$\left\{\begin{array}{c}S=(1+\frac{2(T-T0)}{k+2T0})S0\\ k=\frac{2S0(T1-T0)}{S1-S0}-2T0\end{array}\right.,$

Wherein, S0 gives the sweep limits that the standard sample that thickness is T0 is demarcated, and S1 gives the sweep limits that the standard sample that thickness is T1 is demarcated.

Further, described fitting correction method is related to this step according to what the result of the standard sample actual scanning imaging of the given thickness of a series of differences simulated actual scanning scope and thickness of sample, comprising:

The standard sample adopting the given thickness of a series of difference carries out the scanning imagery of reality, it is thus achieved that piezoelectric ceramics tube scanner is corresponding to the actual scanning scope of each thickness of sample;

Correspond to the actual scanning scope of each thickness of sample according to piezoelectric ceramics tube scanner, adopt fitting algorithm to simulate the actual scanning scope of piezoelectric ceramics tube scanner and the relation curve of thickness of sample or relation function.

Further, described step S2 includes:

S21, the actual (real) thickness inputting sample or the automatic actual (real) thickness obtaining sample;

S22, according to the actual (real) thickness of sample and actual scanning scope and the relation of thickness of sample, adopt off-line postprocessing correction method or on line emendation method that the sweep limits of piezoelectric ceramics tube scanner is corrected.

Further, this step of actual (real) thickness of described automatic acquisition sample, itself particularly as follows:

Travel position according to scanning probe microscope probe screw rod calculates the lifting distance of probe when sample carries out detection imaging automatically, thus accurately calculating the actual (real) thickness of sample.

Further, this step of actual (real) thickness of described automatic acquisition sample, itself particularly as follows:

Mounting distance sensor on the probe of scanning probe microscopy, then passes through the distance between range sensor detection base and gauge head to accurately calculate the actual (real) thickness of sample.

Further, the sweep limits of piezoelectric ceramics tube scanner is corrected this step by described employing off-line postprocessing correction method, itself particularly as follows:

Actual (real) thickness according to sample and actual scanning scope and the relation of thickness of sample, carry out off-line calibration to the result that the detection imaging control system test sample of scanning probe microscopy is obtained, the result after being calibrated.

Further, the sweep limits of piezoelectric ceramics tube scanner is corrected this step by described employing on line emendation method, itself particularly as follows:

Calculating correction method, school for the blind are executed and be integrated in the detection imaging control system of scanning probe microscopy with fitting correction method, and when sample is detected, sweep limits is automatically calibrated by the actual (real) thickness according to sample by detecting imaging control system, directly obtains the result after calibration.

What the present invention taked another solution is that

A kind of sweep limits correction system of piezoelectric ceramics tube scanner, including with lower module:

Chosen module, for from calculating correction method, school for the blind executes selected a kind of sweep limits bearing calibration based on thickness of sample with in fitting correction method, and the actual scanning scope of piezoelectric ceramics tube scanner and the relation of thickness of sample is obtained according to selected bearing calibration, wherein, calculate correction method according to given piezoelectric ceramics length of tube, given sample stage height and the standard sample of 1 given thickness obtain the relation of actual scanning scope and thickness of sample, school for the blind executes the relation obtaining actual scanning scope and thickness of sample according to the standard sample that two given thickness is different, fitting correction method simulates the relation of actual scanning scope and thickness of sample according to the result of the standard sample actual scanning imaging of the given thickness of a series of differences,

Sweep limits correction module, for obtaining the actual (real) thickness of sample, and is corrected the sweep limits of piezoelectric ceramics tube scanner according to the actual (real) thickness of sample and the relation of actual scanning scope and thickness of sample;

The outfan of described chosen module is connected with the input of sweep limits correction module.

The beneficial effects of the method for the present invention is: be additionally arranged calculating correction method, school for the blind executes and fitting correction method, can show that sweep limits is corrected by relation the actual (real) thickness per sample of actual scanning scope and thickness of sample, effectively correct because thickness of sample changes the change of the piezoelectric ceramics tube scanner sweep limits caused, piezoelectric ceramics tube scanner is made to retain on the basis of the advantage such as original high-resolution and low cost, improve the accuracy of testing result, meet scientific research and the industry application high-resolution to scanning probe microscopy, the actual requirement of high accuracy and low cost, more accurately with reliable. further, automatically by the distance between the travel position of scanning probe microscope probe screw rod or the range sensor installed on probe detection base and gauge head, can accurately calculate the thickness of sample, more intelligent. further, after the actual (real) thickness obtaining sample, can select off-line postprocessing correction method or on line emendation method that the sweep limits of piezoelectric ceramics tube scanner is corrected according to actual needs flexibly, more flexibly.

The system of the present invention provides the benefit that: chosen module is additionally arranged calculating correction method, school for the blind executes and fitting correction method, can draw actual scanning scope and thickness of sample relation and in sweep limits correction module actual (real) thickness per sample sweep limits is corrected, effectively correct because thickness of sample changes the change of the piezoelectric ceramics tube scanner sweep limits caused, piezoelectric ceramics tube scanner is made to retain on the basis of the advantage such as original high-resolution and low cost, improve the accuracy of testing result, meet scientific research and the industry application high-resolution to scanning probe microscopy, the actual requirement of high accuracy and low cost, more accurately with reliable.

Accompanying drawing explanation

Fig. 1 is the overall flow figure of the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner of the present invention;

Fig. 2 is the overall structure block diagram of the sweep limits correction system of a kind of piezoelectric ceramics tube scanner of the present invention;

Fig. 3 is probe scanning mode schematic diagram;

Fig. 4 is Sample Scan mode schematic diagram;

Fig. 5 is the structural representation of piezoelectric ceramic tube type scanner;

Fig. 6 is the top view of piezoelectric ceramic tube;

Fig. 7 is the overall structure view of piezoelectric ceramic tube;

Fig. 8 is the motor process schematic diagram of piezoelectric ceramic tube;

Fig. 9 is the motor process comparison diagram of the different-thickness sample of piezoelectric ceramic tube type scanner;

Figure 10 is the motor process schematic diagram calculating piezoelectric ceramic tube corresponding to correction method;

Figure 11 is the structural representation of typical scanning probe microscope probe;

Figure 12 is the structural representation of the scanning probe microscope probe being provided with range sensor.

Accompanying drawing labelling: 1 and 7, sample; 2, probe; 3, scanning device; 4, piezoelectric ceramic tube; 5, base; 6, sample stage; 8, contact conductor; 9, scanning device shell; 10, the first sample; 11, the second sample; 12, gauge head; 13, screw rod; 14, motor; 15, range sensor.

Detailed description of the invention

With reference to Fig. 1, the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner, comprise the following steps:

S1, from calculating correction method, school for the blind executes selected a kind of sweep limits bearing calibration based on thickness of sample with in fitting correction method, and the actual scanning scope of piezoelectric ceramics tube scanner and the relation of thickness of sample is obtained according to selected bearing calibration, wherein, calculate correction method according to given piezoelectric ceramics length of tube, given sample stage height and the standard sample of 1 given thickness obtain the relation of actual scanning scope and thickness of sample, school for the blind executes the relation obtaining actual scanning scope and thickness of sample according to the standard sample that two given thickness is different, fitting correction method simulates the relation of actual scanning scope and thickness of sample according to the result of the standard sample actual scanning imaging of the given thickness of a series of differences,

S2, obtain the actual (real) thickness of sample, and the sweep limits of piezoelectric ceramics tube scanner is corrected by the relation according to the actual (real) thickness of sample and actual scanning scope with thickness of sample.

Being further used as preferred embodiment, described calculating correction method is related to this step according to what the standard sample of given piezoelectric ceramics length of tube, given sample stage height and 1 given thickness obtained actual scanning scope and thickness of sample, itself particularly as follows:

Obtain the relational expression of actual scanning scope S and thickness of sample T according to the standard sample that given piezoelectric ceramics length of tube L, given sample stage height H and 1 given thickness are T0, the relational expression of described actual scanning scope S and thickness of sample T is:

$S=(1+\frac{2(T-T0)}{L+2H+2T0})S0,$

Wherein, S0 is the sweep limits that standard sample is demarcated.

Being further used as preferred embodiment, described school for the blind executes and is related to this step according to what the standard sample that two given thickness is different obtained actual scanning scope and thickness of sample, itself particularly as follows:

Actual scanning scope is performed twice at demarcation by the standard sample according to two given thickness respectively T0 and T1, then show according to the result of twice demarcation that the relational expression of actual scanning scope S and thickness of sample T, the relational expression of described actual scanning scope S and thickness of sample T are:

$\left\{\begin{array}{c}S=(1+\frac{2(T-T0)}{k+2T0})S0\\ k=\frac{2S0(T1-T0)}{S1-S0}-2T0\end{array}\right.,$

Wherein, S0 gives the sweep limits that the standard sample that thickness is T0 is demarcated, and S1 gives the sweep limits that the standard sample that thickness is T1 is demarcated.

Being further used as preferred embodiment, described fitting correction method is related to this step according to what the result of the standard sample actual scanning imaging of the given thickness of a series of differences simulated actual scanning scope and thickness of sample, comprising:

The standard sample adopting the given thickness of a series of difference carries out the scanning imagery of reality, it is thus achieved that piezoelectric ceramics tube scanner is corresponding to the actual scanning scope of each thickness of sample;

Correspond to the actual scanning scope of each thickness of sample according to piezoelectric ceramics tube scanner, adopt fitting algorithm to simulate the actual scanning scope of piezoelectric ceramics tube scanner and the relation curve of thickness of sample or relation function.

Being further used as preferred embodiment, described step S2 includes:

S21, the actual (real) thickness inputting sample or the automatic actual (real) thickness obtaining sample;

S22, according to the actual (real) thickness of sample and actual scanning scope and the relation of thickness of sample, adopt off-line postprocessing correction method or on line emendation method that the sweep limits of piezoelectric ceramics tube scanner is corrected.

Be further used as preferred embodiment, this step of actual (real) thickness of described automatic acquisition sample, itself particularly as follows:

Travel position according to scanning probe microscope probe screw rod calculates the lifting distance of probe when sample carries out detection imaging automatically, thus accurately calculating the actual (real) thickness of sample.

Be further used as preferred embodiment, this step of actual (real) thickness of described automatic acquisition sample, itself particularly as follows:

Mounting distance sensor on the probe of scanning probe microscopy, then passes through the distance between range sensor detection base and gauge head to accurately calculate the actual (real) thickness of sample.

Being further used as preferred embodiment, the sweep limits of piezoelectric ceramics tube scanner is corrected this step by described employing off-line postprocessing correction method, itself particularly as follows:

Actual (real) thickness according to sample and actual scanning scope and the relation of thickness of sample, carry out off-line calibration to the result that the detection imaging control system test sample of scanning probe microscopy is obtained, the result after being calibrated.

Being further used as preferred embodiment, the sweep limits of piezoelectric ceramics tube scanner is corrected this step by described employing on line emendation method, itself particularly as follows:

Calculating correction method, school for the blind are executed and be integrated in the detection imaging control system of scanning probe microscopy with fitting correction method, and when sample is detected, sweep limits is automatically calibrated by the actual (real) thickness according to sample by detecting imaging control system, directly obtains the result after calibration.

With reference to Fig. 2, the sweep limits of a kind of piezoelectric ceramics tube scanner corrects system, including with lower module:

Chosen module, for from calculating correction method, school for the blind executes selected a kind of sweep limits bearing calibration based on thickness of sample with in fitting correction method, and the actual scanning scope of piezoelectric ceramics tube scanner and the relation of thickness of sample is obtained according to selected bearing calibration, wherein, calculate correction method according to given piezoelectric ceramics length of tube, given sample stage height and the standard sample of 1 given thickness obtain the relation of actual scanning scope and thickness of sample, school for the blind executes the relation obtaining actual scanning scope and thickness of sample according to the standard sample that two given thickness is different, fitting correction method simulates the relation of actual scanning scope and thickness of sample according to the result of the standard sample actual scanning imaging of the given thickness of a series of differences,

Sweep limits correction module, for obtaining the actual (real) thickness of sample, and is corrected the sweep limits of piezoelectric ceramics tube scanner according to the actual (real) thickness of sample and the relation of actual scanning scope and thickness of sample;

The outfan of described chosen module is connected with the input of sweep limits correction module.

Below in conjunction with Figure of description and specific embodiment, the present invention is described in further detail.

Embodiment one

Ultimate principle and the involved correlation theory of the present invention are illustrated by the present embodiment.

Scanning probe microscopy controls probe by piezoelectric scanner and sample surfaces is scanned, and the interaction signal of synchronous detecting and record probe and sample, thus obtaining the surface information of sample. Sample Scan is actually the controlled relative motion of probe and sample by probe, both can adopt the mode of probe scanning, it is possible to adopt the mode of Sample Scan, as shown in Figures 3 and 4.

In Fig. 3 and 4,1 is sample, and 2 is probe, and 3 is piezoelectric scanner, and Fig. 3 is probe scanning mode, and Fig. 4 is Sample Scan mode. Actually, the scanning motion of probe and sample is both relative motioies, both modes are equivalent, but current scanning probe microscopy, generally it is integrated with multiple detection technique and probe many employings laser detection mode, needs the relative position keeping probe and laser detection system constant in the process of detection, it is relatively big that the mode adopting probe scanning implements difficulty, therefore scanning probe microscopy adopts Sample Scan mode mostly.

In the way of Sample Scan, the process that realizes of invention is illustrated below.

The principle of piezoelectric scanner is the piezoelectric inverse effect utilizing piezoelectric, by voltage, motion is accurately controlled. Piezoelectric scanner mainly has piezo-ceramic tube type and flatbed etc., wherein, due to piezoelectric ceramic tube type scanner have that volume is little, the advantage such as simple in construction, good stability, fast response time, driving are easy to control, it is current resolution piezoelectric scanner type high, the most with low cost, therefore it is most widely used in scanning probe microscopy.

As it is shown in figure 5, wherein, 4 is piezoelectric ceramic tube to the structure of piezoelectric ceramic tube type scanner; 5 is insulator foot, plays fixation, is generally formed by Ceramic manufacturing, have good insulating properties and mechanical stability; 6 is insulated sample platform, and lower end is connected with piezoelectric ceramic tube, and sample 7 is placed on it, and 8 is contact conductor, and 9 is the shell of scanning device.

Piezoelectric ceramic tube is the core of piezoelectric ceramic tube type scanner, and its structure is as shown in Figures 6 and 7. In Fig. 6 and 7, piezoelectric ceramic tube radially polarizes, and wall electrode is split by four-quadrant, and constitutes 5 independent electrodes with inwall electrode Z, represents with+X ,-X ,+Y ,-Y and Z respectively.

As shown in Figure 8, when the voltage of Z electrode increases, divided 4 parts of earthenware electric field intensity from inside to outside is gradually increased, and this 4 part axially simultaneously extends, and creates moving along Z-direction. When the voltage of+X electrode increase, the voltage of-X electrode reduce time, the divided right part of earthenware electric field intensity from inside to outside reduces, and shortens vertically; And the electric field intensity that left part is from inside to outside increases, axially elongated. This side of earthenware is shortened and the deformation of opposite side elongation causes that its upper end bends to the right, produce the motion of X-direction. In like manner, the change in voltage of+Y and-Y electrode also can produce the motion of Y-direction.Therefore, wall electrode presses the single earthenware of four-quadrant segmentation, by the voltage of 5 electrodes is controlled, it is possible to realize the motion of X-Y-Z three-dimensional.

The X-Y scanning direction motion of piezoelectric ceramic tube type scanner is what to be realized by the Bending Deformation of piezoelectric ceramic tube, if therefore thickness of sample is different, even if system drives scanning device to do identical motion, the move distance of the sample upper surface that probe detects also differs, as shown in Figure 9. In Fig. 9,10 is the first sample that thickness is T1, and 11 is the second sample that thickness is T2, and 4 is piezoelectric scanning pipe, and 5 is insulator foot, and 6 is scanning device sample stage. As seen from Figure 9, when system drive scanatron is scanned, the displacement of the first sample is S1, the displacement of the second sample is S2, if T2 is > T1, then S2 > S1, namely sample is more thick, and actual sweep limits (i.e. displacement) is more big.

The side that the deformation of piezoelectric ceramic tube is pipe is shortened and opposite side elongation generation, but the physical length for the piezoelectric ceramic tube of scanning probe microscopy piezoelectric scanner is relatively larger, commonly use as 30mm, that minimum is also about 10mm, the border benefit of its upper and lower end face can be ignored, therefore shape can carry out matching by circular arc line after piezoelectric ceramic tube deformation, as shown in Figure 10. In Figure 10, A is the central point of the fixing end face of piezoelectric ceramic tube, the central point of piezoelectric ceramic tube motion end face when B is do not apply turntable driving voltage, B ' is the central point of piezoelectric ceramic tube motion end face, the center of circle of piezoelectric ceramic tube circular arc when O is deformation after applying turntable driving voltage generation deformation; L is the length of piezoelectric ceramic tube, H is the height of sample stage, T0 is the thickness of the standard sample for calibrating piezoelectric ceramic tube sweep limits, T is the actual (real) thickness of sample, St is the displacement of piezoelectric ceramic tube motion end face, S0 is the displacement of standard sample, and S is the actual displacement of sample.

Assume that ∠ BAB ' is for θ, then have:

St=L tan θ (1)

Due to AC and B ' circular arc that formed after C ' respectively piezoelectric ceramic tube deformation at the tangent line of A and B ' 2, ∠ DB ' C '=2 ∠ BAB '=2 θ can be demonstrate,proved to obtain by simple geometric proof. Therefore, have according to geometrical relationship:

S0=St+ (H+T0) tan2 θ (2)

S=St+ (H+T) tan2 θ (3)

And for the piezoelectric scanning pipe in scanning probe microscopy, its pipe range L is generally 30mm, under the driving of voltage, the displacement St that its bending produces is 10 μm of magnitudes, and θ is very little, only 10^-4Magnitude, therefore have: tan θ=θ, tan2 θ=2 θ. Therefore, formula (2) and (3) can be rewritten as:

S0=St+2 (H+T0) θ (4)

S=St+2 (H+T) θ (5)

Can be obtained by formula (1), (4) and (5) simultaneous:

$S=(1+\frac{2(T-T0)}{L+2H+2T0})S0---\left(6\right)$

For the manufacturer of instrument, with length be L piezoelectric ceramic tube, height be the sample stage assembling scanning device of H, the sweep limits of scanning device is once demarcated by the standard sample having only to when dispatching from the factory adopt thickness to be T0, can obtain S0. In reality is measured, only it is to be understood that the thickness T of sample, just obtain, from formula (6), the actual scanning scope that this scanning device is current, the measurement error that effectively correction causes because of thickness of sample change, it is achieved the high accuracy (the method is referred to as calculating correction method) of testing result.

For the user of instrument, all have employed protection shell due to scanning device and carry out accurate encapsulation, it is impossible to accurately obtain the length L of piezoelectric ceramic tube and the height H of sample stage.In order to the actual scanning scope encapsulating piezoelectric ceramics tube scanner of unknown piezoelectric ceramic tube and sample stage yardstick is corrected, the present invention proposes the blind correction method of a kind of piezoelectric ceramics tube scanner. The ultimate principle that the school for the blind of piezoelectric ceramics tube scanner executes is as follows:

Can be obtained by formula (6):

$L+2H=\frac{2S0(T-T0)}{S-S0}-2T0---\left(7\right)$

The geometric parameter k of definition piezoelectric ceramics tube scanner:

K=L+2H (8)

Then formula (7) can be rewritten as:

$k=\frac{2S0(T-T0)}{S-S0}-2T0---\left(9\right)$

User for instrument, the sweep limits of scanning device is carried out demarcation and obtains S0 by the standard sample first adopting thickness to be T0, the standard sample adopting thickness to be T1 again (can pad below the standard sample that thickness is T0 in reality and put the pad that thickness is t, then T1=T0+t) sweep limits of scanning device is carried out demarcation obtain S1, T0, S0, T1, S1 are substituted into formula (8), and the geometric parameter expression formula that can obtain scanning device is:

$k=\frac{2S0(T1-T0)}{S1-S0}-2T0---\left(10\right)$

Can be obtained by formula (6) and formula (8) simultaneous:

$S=(1+\frac{2(T-T0)}{k+2T0})S0---\left(11\right)$

That is, although there is no piezoelectric ceramic tube and sample stage scale parameter, scanning device sweep limits still can be carried out many demarcation once by the standard sample adopting another thickness different by the user of instrument again, obtain the geometric parameter k of scanning device, and after determining the value of k, in actual measurement, only it is to be understood that the actual (real) thickness T of sample, just can obtain, from formula (11), the actual scanning scope that this scanning device is current, the measurement error that effectively correction causes because of thickness of sample change, it is achieved the high accuracy of testing result.

Owing to the actual scanning scope of scanning device and the thickness of sample have dependency, the invention allows for another kind of calibration steps fitting correction method, the method adopts the standard sample of a series of different-thickness to carry out the scanning imagery of reality, obtain this scanning device actual scanning scope corresponding to each thickness of sample, thus simulating the actual scanning scope of this scanning device and the relation curve of thickness of sample or function, then with the relation curve simulated or function for foundation, the change of the actual scanning scope that thickness of sample is caused is calibrated. Fitting correction method is a kind of empirical formula calibration steps based on experimental data, as long as the standard sample quantity of selected a series of different-thickness is abundant and institute's likely thickness of sample in the thickness range covering actually used process of instrument, thickness can be left out the one-tenth of sweep limits generation impact is former, therefore it applies also for the other types scanning device of non-piezoelectric earthenware.

And for the change of the sweep limits caused by thickness of sample, user can adopt above-mentioned calculating correction method, school for the blind to execute and be corrected with fitting correction method these three method, it is thus achieved that the relation of actual scanning scope and thickness of sample. After obtaining the relation of actual scanning scope and thickness of sample, can adopt on line emendation method or off-line postprocessing correction method that the sweep limits of piezoelectric ceramics tube scanner is corrected by actual (real) thickness per sample.

Wherein, the off-line postprocessing correction method of sweep limits, refer to after utilizing scanning probe microscopy to obtain testing result, consider that the actual (real) thickness of sample is measured by the measurement error that thickness of sample causes, and introduce this parameter of thickness of sample, the testing result obtained is calibrated, it is thus achieved that the result after calibration, this result eliminates the thickness of sample impact on sweep limits, is effectively increased the accuracy of testing result. It is unrelated that off-line postprocessing correction rule controls system with scanning probe microscopy, only need to understand the data form of testing result, can be calibrated, and generates the new data after calibration.

And the on line emendation method of sweep limits, refer to and calculating correction method, school for the blind are executed and be integrated in the detection imaging control system of scanning probe microscopy with fitting correction method, when sample is detected, by the actual (real) thickness input system of sample or the actual (real) thickness automatically obtaining sample, sweep limits is automatically calibrated by detection imaging control system again with actual (real) thickness, eliminate the thickness of sample impact on sweep limits, directly obtain calibrated result, be effectively increased the accuracy of testing result.

Compared with off-line postprocessing correction method, on line emendation method is convenient, but on line emendation method needs the online scan control software that scanning probe microscopy controls system to modify, apparatus manufacture does not generally provide a user with source program or development interface, therefore on line emendation method is generally only applicable to apparatus manufacture and embeds it in control system, the performance of instrument is made to be promoted.

Although the present embodiment is fixed based on probe, the scanning probe microscopy of Sample Scan formula, but for probe scanning, sample is fixing is scanning probe microscopy, the calibration steps of the present embodiment is equally applicable, and the calibration steps of the present embodiment is also applied for the calibration of other instrument actual motion strokes adopting piezoelectric ceramics (particularly piezoelectric ceramic tube) to drive.

Embodiment two

In order to improve the automaticity of scanning probe microscopy, user is made to use more convenient, for scanning probe microscopy, the present invention proposes the technology that thickness of sample carries out measurement automatically, this technology in conjunction with the embodiments one sweep limits bearing calibration, when sample is detected, thickness of sample can be automatically obtained, it is achieved the automatic on-line correction of sweep limits.

Automatically the structure of the scanning probe microscope probe used is measured as shown in figure 11. In Figure 11,12 is gauge head, and 5 is base, and 2 is probe, and 3 is scanning device, and 1 is sample, and 13 is accurate screw rod, and 14 is motor. Scanning probe microscopy is controlled the probe in probe by system and sample surfaces is scanned obtaining the surface information of sample, probe is main, and by gauge head and base, (Figure 11 is in order to show understructure, only draw base and upper cover) constitute, probe is arranged on gauge head, sample is fixed on the sample stage above scanning device, scanning device is arranged on base, gauge head is by three accurate Screw rod bearingses on base, each accurate screw rod rotates under the control of a motor drives, do elevating movement, the automatic measurement requirement of sample to adapt to different-thickness. During detection imaging, probe contact with sample or with sample maintenance nanoscale (namely 10^-9M magnitude) spacing and scan at the upper surface of sample, accurate screw rod then thickness per sample carries out lift adjustment, and sample is more thick, and screw rod rises more high. In order to ensure level and the stability thereof of gauge head, detection imaging control system runs three screw rod synchronization liftings of drive by controlling three stepping motor synchronous. And, even if three screw rods can not synchronization lifting, the position according to three screw rods and probe, by the travel position of each screw rod, also can automatically calculate the lifting distance of probe when sample is carried out detection imaging, thus accurately calculating the actual (real) thickness of sample.

The automatic measurement technology of another kind of thickness of sample is to be realized by the probe mounting distance sensor at scanning probe microscopy, as shown in figure 12. In Figure 12,12 is gauge head, and 5 is base, and 2 is probe, and 3 is scanning device, and 1 is sample, and 13 is accurate screw rod, and 14 is motor, and 15 is range sensor. The distance between base and gauge head directly measured by range sensor 15. When detecting imaging, accurate screw rod thickness per sample carries out lift adjustment, and sample is more thick, screw rod rises to get over Gao Yue, distance between gauge head and base is more big, therefore according to range sensor detect sample time gauge head and base between distance, also can accurately calculate the thickness of sample.

The present embodiment obtains the travel position of screw rod according to the position of scanning probe microscope probe screw rod and probe, or mounting distance sensor detects the distance between base and gauge head on probe, automatically accurately to calculate the thickness of sample, with this in conjunction with the embodiments one bearing calibration actual scanning scope is calibrated automatically, directly obtain the test result after calibration.

The method and structure of the present embodiment is desirably integrated in scanning probe microscopy, realize the full-automatic correction of the real-time online sweep limits of scanning probe microscopy, namely scanning probe microscopy is when filling sample inserting needle, automatically obtain the actual (real) thickness of sample, then with this thickness, sweep limits being carried out real time calibration inside scanning imaging system, its testing result is really the accurate result after correction.

The sweep limits bearing calibration of the piezoelectric ceramic tube that the present invention proposes, effectively correct because thickness of sample changes the measurement error causing the change of piezoelectric ceramics tube scanner sweep limits to bring, piezoelectric ceramics tube scanner is made to retain on the basis of the advantages such as original high-resolution, low cost, realize the high accuracy of testing result, meet scientific research and the industry application actual requirement to the high-resolution of scanning probe microscopy, high accuracy and low cost.

It is above the preferably enforcement of the present invention has been illustrated, but the invention is not limited to described embodiment, those of ordinary skill in the art also can make all equivalent variations or replacement under the premise without prejudice to spirit of the present invention, and these equivalent deformation or replacement are all contained in the application claim limited range.

Claims (10)

1. the sweep limits bearing calibration of a piezoelectric ceramics tube scanner, it is characterised in that: comprise the following steps:

S1, from calculating correction method, school for the blind executes selected a kind of sweep limits bearing calibration based on thickness of sample with in fitting correction method, and the actual scanning scope of piezoelectric ceramics tube scanner and the relation of thickness of sample is obtained according to selected bearing calibration, wherein, calculate correction method according to given piezoelectric ceramics length of tube, given sample stage height and the standard sample of 1 given thickness obtain the relation of actual scanning scope and thickness of sample, school for the blind executes the relation obtaining actual scanning scope and thickness of sample according to the standard sample that two given thickness is different, fitting correction method simulates the relation of actual scanning scope and thickness of sample according to the result of the standard sample actual scanning imaging of the given thickness of a series of differences,

S2, obtain the actual (real) thickness of sample, and the sweep limits of piezoelectric ceramics tube scanner is corrected by the relation according to the actual (real) thickness of sample and actual scanning scope with thickness of sample.

2. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 1, it is characterized in that: described calculating correction method is related to this step according to what the standard sample of given piezoelectric ceramics length of tube, given sample stage height and 1 given thickness obtained actual scanning scope and thickness of sample, itself particularly as follows:

Obtain the relational expression of actual scanning scope S and thickness of sample T according to the standard sample that given piezoelectric ceramics length of tube L, given sample stage height H and 1 given thickness are T0, the relational expression of described actual scanning scope S and thickness of sample T is:

$S=(1+\frac{2(T-T0)}{L+2H+2T0})S0,$

Wherein, S0 is the sweep limits that standard sample is demarcated.

3. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 1, it is characterized in that: described school for the blind executes and is related to this step according to what the standard sample that two given thickness is different obtained actual scanning scope and thickness of sample, itself particularly as follows:

Actual scanning scope is performed twice at demarcation by the standard sample according to two given thickness respectively T0 and T1, then show according to the result of twice demarcation that the relational expression of actual scanning scope S and thickness of sample T, the relational expression of described actual scanning scope S and thickness of sample T are:

$\left\{\begin{array}{c}S=(1+\frac{2(T-T0)}{k+2T0})S0\\ k=\frac{2S0(T1-T0)}{S1-S0}-2T0\end{array}\right.,$

Wherein, S0 gives the sweep limits that the standard sample that thickness is T0 is demarcated, and S1 gives the sweep limits that the standard sample that thickness is T1 is demarcated.

4. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 1, it is characterized in that: described fitting correction method is related to this step according to what the result of the standard sample actual scanning imaging of the given thickness of a series of differences simulated actual scanning scope and thickness of sample, comprising:

The standard sample adopting the given thickness of a series of difference carries out the scanning imagery of reality, it is thus achieved that piezoelectric ceramics tube scanner is corresponding to the actual scanning scope of each thickness of sample;

Correspond to the actual scanning scope of each thickness of sample according to piezoelectric ceramics tube scanner, adopt fitting algorithm to simulate the actual scanning scope of piezoelectric ceramics tube scanner and the relation curve of thickness of sample or relation function.

5. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 1, it is characterised in that: described step S2 includes:

S21, the actual (real) thickness inputting sample or the automatic actual (real) thickness obtaining sample;

S22, according to the actual (real) thickness of sample and actual scanning scope and the relation of thickness of sample, adopt off-line postprocessing correction method or on line emendation method that the sweep limits of piezoelectric ceramics tube scanner is corrected.

6. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 5, it is characterised in that: this step of actual (real) thickness of described automatic acquisition sample, itself particularly as follows:

Travel position according to scanning probe microscope probe screw rod calculates the lifting distance of probe when sample carries out detection imaging automatically, thus accurately calculating the actual (real) thickness of sample.

7. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 5, it is characterised in that: this step of actual (real) thickness of described automatic acquisition sample, itself particularly as follows:

Mounting distance sensor on the probe of scanning probe microscopy, then passes through the distance between range sensor detection base and gauge head to accurately calculate the actual (real) thickness of sample.

8. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 5, it is characterised in that: the sweep limits of piezoelectric ceramics tube scanner is corrected this step by described employing off-line postprocessing correction method, itself particularly as follows:

Actual (real) thickness according to sample and actual scanning scope and the relation of thickness of sample, carry out off-line calibration to the result that the detection imaging control system test sample of scanning probe microscopy is obtained, the result after being calibrated.

9. the sweep limits bearing calibration of a kind of piezoelectric ceramics tube scanner according to claim 5,6 or 7, it is characterised in that: the sweep limits of piezoelectric ceramics tube scanner is corrected this step by described employing on line emendation method, itself particularly as follows:

Calculating correction method, school for the blind are executed and be integrated in the detection imaging control system of scanning probe microscopy with fitting correction method, and when sample is detected, sweep limits is automatically calibrated by the actual (real) thickness according to sample by detecting imaging control system, directly obtains the result after calibration.

10. the sweep limits correction system of a piezoelectric ceramics tube scanner, it is characterised in that: include with lower module:

Chosen module, for from calculating correction method, school for the blind executes selected a kind of sweep limits bearing calibration based on thickness of sample with in fitting correction method, and the actual scanning scope of piezoelectric ceramics tube scanner and the relation of thickness of sample is obtained according to selected bearing calibration, wherein, calculate correction method according to given piezoelectric ceramics length of tube, given sample stage height and the standard sample of 1 given thickness obtain the relation of actual scanning scope and thickness of sample, school for the blind executes the relation obtaining actual scanning scope and thickness of sample according to the standard sample that two given thickness is different, fitting correction method simulates the relation of actual scanning scope and thickness of sample according to the result of the standard sample actual scanning imaging of the given thickness of a series of differences,

Sweep limits correction module, for obtaining the actual (real) thickness of sample, and is corrected the sweep limits of piezoelectric ceramics tube scanner according to the actual (real) thickness of sample and the relation of actual scanning scope and thickness of sample;

The outfan of described chosen module is connected with the input of sweep limits correction module.