CN103231311A - Method for optimizing preparation of chemical mechanical polishing fluid - Google Patents

Abstract

The invention provides a method for optimizing preparation of a chemical mechanical polishing fluid. The method comprises the steps of selecting process conditions for chemical mechanical polishing and obtaining wafer characteristic data and current polishing fluid preparation data; obtaining polishing particle absorption state data through a polymer reference action point model; judging whether the polishing particle absorption state data meet a physical absorption state standard or not; if the polishing particle absorption state data do not meet the physical absorption state standard, adjusting the current polishing fluid preparation data, returning the step of obtaining of the polishing particle absorption state data to after adjustment; and if the polishing particle absorption state data meet the physical absorption state standard, enabling the current polishing fluid preparation data to serve as polishing fluid preparation optimizing data, and preparing and obtaining the optimized polishing fluid according to the polishing fluid preparation optimizing data. The preparation of the chemical mechanical polishing fluid is optimized through the method, so that the optimizing process is simplified, and on the premise that polishing particles adsorbed on wafer surfaces after polishing are removed easily, the process optimizing cost of the chemical mechanical polishing fluid can be reduced, and the process optimizing period of the chemical mechanical polishing fluid can be shortened.

Description

A kind of method of chemical-mechanical grinding liquid configuration optimization

Technical field

The present invention relates to the hyperfine Surface-micromachining process of IC chip field, particularly a kind of method for the chemical-mechanical grinding liquid configuration optimization of controlling the adsorbed state of abrasive grains on crystal column surface.

Background technology

Along with constantly reducing of integrated circuit fabrication process characteristic size, ic manufacturing technology has run into unprecedented challenge.Especially, in the main flow fabrication of semiconductor device below 32/28nm, the flatness of circuit surface is the key factor that influences photoetching depth of focus level and yields.Therefore, how to realize the hyperfine important technological problems that is processed into current integrated circuit fabrication process of semiconductor chip surface.At present, realize the hyperfine processing of chip surface, most popular planarization is cmp (CMP) technology.

As shown in Figure 1, the device of cmp is wafer to be adsorbed on wafer carry on the device, then with wafer by on the grinding pad that is pressed in the rotary table surface, simultaneously the lapping liquid that contains compositions such as abrasive grains, oxidant and surfactant to the grinding pad input is immersed in the lapping liquid wafer.In the process of lapping, remove at chemical etching and two kinds of materials of mechanical grinding under the reciprocation of mechanism and make crystal column surface reach planarization.

In ic manufacturing process and since characteristic size reduce directly cause various microeffects to occur, the abrasive grains in the chemical-mechanical grinding liquid is adsorbed on the crystal column surface because of intermolecular interaction easily.Along with the growth of time, this adsorbed state will become the chemisorbed that is difficult to separate by the physical absorption that is easy to desorb, and then make abrasive grains to remove from crystal column surface, thereby influence the degree of planarization of crystal column surface.So as seen, the control abrasive grains makes the adsorbed state of abrasive grains on crystal column surface be in the physical absorption of easy desorb at the adsorbed state of crystal column surface, just becomes the realization abrasive grains and removes important technological problems from crystal column surface.

For avoiding abrasive grains to adsorb at crystal column surface, common means are to add high molecular surfactant in lapping liquid.When abrasive grains physics is adsorbed in crystal column surface; surfactant molecule can reduce the active force between wafer and abrasive grains; abrasive grains is reduced in the suction-operated of crystal column surface and can not change chemisorbed into; and; surfactant molecule can form fine and close particle protective layer at abrasive grains and crystal column surface; prevent that abrasive grains and crystal column surface from forming further absorption, the adsorbed state control of abrasive grains on crystal column surface is in the physical absorption stage the most at last.

Can control abrasive grains at the adsorbed state of crystal column surface although in lapping liquid, add high molecular surfactant, but utilize in the process that lapping liquid grinds wafer actual, configuration factors such as the kind of surfactant, size, concentration, distribution of charges all can produce very big influence to the control effect of adsorbed state in the lapping liquid; And, under the different fabrication process conditions, because abrasive grains is different in wafer and the lapping liquid, the configuration of required surfactant is also different, therefore, how to optimize the configuration of surfactant in the lapping liquid, just become in the chemical-mechanical grinding liquid production and control abrasive grains in the important step of crystal column surface adsorbed state.

In the present prior art, the main means of lapping liquid configuration are still optimized in experiment, a kind of lapping liquid process for preparation of concrete optimization surfactant component is: according to kinds of surfactants, size, the empirical value configuration lapping liquid of physical chemical factors such as concentration, the concrete test experiments that then lapping liquid that configures is used for cmp processing, determine the adsorbed state of abrasive grains on crystal column surface with the method for experiment measuring, take all factors into consideration the abrasive grains adsorbed state that experiment obtains again, abrasive grains cleans the configuration parameter that factors such as difficulty and lapped face planarization effect are adjusted surfactant in the lapping liquid; So circulation, finally obtain a kind of configuration optimization lapping liquid, guaranteeing to make abrasive grains remove from crystal column surface easily under the conditions such as surface and grinding rate when this lapping liquid is used for chemical mechanical milling tech.

Yet, because integrated circuit fabrication process requires high to experimental situation and measurement device, the random fluctuation of experiment itself and technology fluctuation etc. have considerable influence to the levels of precision of experimental measurements, and need continuous repeated experiments process to adjust the configuration of lapping liquid, therefore, the abrasive grains that is adsorbed on the crystal column surface at the adsorbed state of crystal column surface, after making grinding for the control abrasive grains is eliminated easily, means are optimized the lapping liquid configuration fully by experiment, cost is higher, and the cycle is also longer.

Summary of the invention

The problem to be solved in the present invention provides a kind of method of chemical-mechanical grinding liquid configuration optimization, make it to be in the physical absorption state of easy desorb with the control abrasive grains at the adsorbed state of crystal column surface, and can overcome problems such as the cost that the existing method of optimizing lapping liquid configuration by experiment brings is higher, the cycle is long.

For achieving the above object, the invention provides a kind of method of chemical-mechanical grinding liquid configuration optimization, said method comprising the steps of:

Steps A: the process conditions of selected cmp;

Step B: according to selected process conditions, material when obtaining crystal column surface and grinding is as the wafer characteristics data, and kind, size, concentration and the distribution of charges of obtaining kind, size, concentration and the distribution of charges of abrasive grains in the default lapping liquid and surfactant are as current lapping liquid configuration data;

Step C: according to described wafer characteristics data and described current lapping liquid configuration data, by macromolecule reference role point model, obtain the abrasive grains adsorbed state data corresponding with described current lapping liquid configuration data;

Step D: judge that whether described abrasive grains adsorbed state data satisfy physical absorption state standard, if not, enter step e, if enter step F;

Step e: adjust described current lapping liquid configuration data, and the lapping liquid configuration data after will adjusting is as described current lapping liquid configuration data; Enter step C;

Step F: with described current lapping liquid configuration data as lapping liquid configuration optimization data, and the lapping liquid that utilizes lapping liquid configuration optimization data configuration to be optimized.

Preferably, described step C comprises:

Step C11: according to the material of crystal column surface in the described wafer characteristics data, and kind, size, concentration and the distribution of charges of abrasive grains and kind, size, concentration and the distribution of charges of surfactant molecule in the described current lapping liquid configuration data, by the distribution function theory, obtain correlation function in the molecule of surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains;

Step C12: according to correlation function in the molecule of described surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains, find the solution macromolecule reference role point model integral equation, obtain the radial distribution function that reaches between crystal column surface and surfactant molecule between crystal column surface and abrasive grains;

Step C13: obtain the peak height of the peak height of radial distribution function between described crystal column surface and surfactant molecule and the radial distribution function between length and crystal column surface and abrasive grains and length as the abrasive grains adsorbed state data under the current configuration.

Preferably, described step D comprises: judge that the peak height of the radial distribution function between crystal column surface described in the described abrasive grains adsorbed state data and surfactant molecule whether greater than default peak height threshold value, if not, enters step e, if enter step F.

Preferably, described step D comprises: judge that the peak value length of the radial distribution function between crystal column surface described in the described lapping liquid particle adsorbed state data and abrasive grains whether greater than default peak value length threshold value, if not, enters step e, if enter step F.

Preferably, described step C comprises:

Step C21: according to the material of crystal column surface in the described wafer characteristics data, and kind, size, concentration and the distribution of charges of abrasive grains and kind, size, concentration and the distribution of charges of surfactant molecule in the described current lapping liquid configuration data, by the distribution function theory, obtain correlation function in the molecule of surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains;

Step C22: according to correlation function in the molecule of described surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains, find the solution macromolecule reference role point model integral equation, obtain between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the radial distribution function between crystal column surface and abrasive grains;

Step C23: according between described surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the radial distribution function between crystal column surface and abrasive grains, obtain the solvation free energy of current grinding system;

Step C24: obtain the solvation free energy of current grinding system as the abrasive grains adsorbed state data under the current configuration.

Preferably, described step D comprises: judge that the solvation free energy of current grinding system in the described abrasive grains adsorbed state data whether less than default free energy threshold value, if not, enters step e, if enter step F.

Preferably, the described theoretical integral equation of macromolecule reference role point model of finding the solution comprises: described macromolecule reference role point model integral equation is converted into the Fourier matrix form, and adopts the Fourier conversion to find the solution in conjunction with the numerical method of revising direct iteration subspace.

Preferably, described step e is to comprise: kind, size, concentration and the distribution of charges of the abrasive grains in the current lapping liquid configuration data are fixed, adjust kind, size, concentration and/or the distribution of charges of the surfactant in the current lapping liquid configuration data, and the lapping liquid configuration data after will adjusting is as described current lapping liquid configuration data; Enter step C.

Preferably, also comprise after the step F: with lapping liquid configuration optimization data, be stored in the lapping liquid configuration database with the corresponding relation of described selected process conditions, the abrasive grains adsorbed state data that described lapping liquid is distributed the data correspondence rationally satisfy described physical absorption state.

Preferably, also comprise after the step F: utilize the lapping liquid of described optimization under the process conditions of described selected cmp, wafer to be ground, and after grinding the cleaning wafer surface stage remove the abrasive grains of crystal column surface.

Compared with prior art, the present invention has the following advantages:

The present invention obtains wafer characteristics data and current lapping liquid configuration data according to selected process conditions, utilize macromolecule reference point model to abrasive grains in the lapping liquid, the spatial distribution of surfactant and crystal column surface characterizes, thereby analyze the abrasive grains adsorbed state data that obtain under the current lapping liquid configuration, judge whether these abrasive grains adsorbed state data satisfy physical absorption state standard, according to differentiating the result current lapping liquid configuration data is adjusted again, be met the target lapping liquid configuration data of physical absorption state standard, to satisfy the current lapping liquid configuration data of physical absorption state standard at last as lapping liquid configuration optimization data, and the lapping liquid that utilizes this lapping liquid configuration optimization data configuration to be optimized.Like this, adjustment and the optimization of chemical-mechanical grinding liquid configuration, can utilize macromolecule reference role point model to differentiate the lapping liquid of current configuration when grinding wafer, whether abrasive grains is in the physical absorption state of easy desorb at the adsorbed state of crystal column surface, thereby, the optimizing process of lapping liquid configuration is simplified, and is adsorbed on after guaranteeing to grind when abrasive grains on the crystal column surface is easy to remove, and process optimization cost and the cycle of chemical-mechanical grinding liquid all are minimized.

Description of drawings

Fig. 1 is the equipment pie graph of cmp in the prior art;

Fig. 2 is the basic flow sheet of method one embodiment of chemical-mechanical grinding liquid configuration optimization of the present invention;

Fig. 3 is the flow chart that the present invention obtains method one embodiment of abrasive grains adsorbed state data;

Fig. 4 is the flow chart that the present invention obtains the another embodiment of method of abrasive grains adsorbed state data;

Fig. 5 is the flow chart of an embodiment of the solution of macromolecule reference role point model integral equation of the present invention;

Fig. 6 is the flow chart that the present invention finds the solution an embodiment of the step that macromolecule reference role point model integral equation obtains each radial distribution function;

Fig. 7 is the basic flow sheet that the present invention adjusts an embodiment of current lapping liquid configuration data.

The specific embodiment

Below we will be by reference to the accompanying drawings, optimum implementation of the present invention is described in detail.At first it is to be noted, the implication of the term of using among the present invention, words and claim can not only only limit to its literal and common implication and go to understand, the implication and the concept that also comprise and then conform to technology of the present invention, this is because we are as the inventor, to suitably provide the definition of term, in order to the most appropriate description is carried out in our invention.Therefore, the configuration that provides in this explanation and the accompanying drawing is first-selected embodiment of the present invention, rather than will enumerates all technical characteristics of the present invention.We will recognize to also have various equivalent scheme or the modifications that can replace our scheme.

As shown in Figure 2 be, the basic flow sheet of an embodiment of the method for chemical-mechanical grinding liquid configuration optimization of the present invention, this method comprises the steps:

The process conditions of step 201, selected cmp:

According to actual machining informations such as the kind of the concrete wafer of required grinding, materials, the process conditions of selected concrete cmp are as the rotating speed of flow rate, wafer and the grinding pad of lapping liquid, external pressure, temperature etc.

Step 202, the selected process conditions of basis, material when obtaining crystal column surface and grinding is as the abrasive characteristic data, and kind, size, concentration and the distribution of charges of obtaining kind, size, concentration and the distribution of charges of abrasive grains in the default lapping liquid and surfactant are as current lapping liquid configuration data:

Abrasive grains in the default lapping liquid and kind, size, concentration and the distribution of charges etc. of high molecular surfactant molecule are actually the empirical value according to the definite lapping liquid configuration of selected process conditions.In the cmp processing procedure, for different actual process, corresponding lapping liquid configuration empirical value is arranged.In the present embodiment, need obtain a kind of concrete lapping liquid configuration parameter as initial value, lapping liquid configuration is adjusted and optimized with this initial value, so, in this step, the empirical value that will dispose according to the lapping liquid that selected process conditions are determined is as initial value, so that present embodiment can be achieved.

Need to prove that this step is obtained current lapping liquid configuration data according to empirical value can numerous embodiments.For example, for obtaining of these default lapping liquid configuration datas of kind, size, concentration and distribution of charges of abrasive grains and surfactant, can search and obtain corresponding preset lapping liquid configuration data in default lapping liquid configuration database according to process conditions, this default lapping liquid configuration database stores the empirical value according to kind, size, concentration and the distribution of charges of the abrasive grains of corresponding process conditions preservation and surfactant.Be understandable that, this step 202 is actually the empirical data of obtaining the lapping liquid configuration according to process conditions, above-mentioned example is a kind of of embodiment, the empirical value of lapping liquid configuration data is not must be stored in the database, and present embodiment also can adopt other to obtain the implementation of lapping liquid configuration empirical value.

In addition, in the present embodiment, surfactant can be for high molecular, also can be for micromolecular.Because the amphipathic segment of high molecular surfactant is objectionable intermingling each other, and microphase-separated takes place easily, make it in surface and body construction, present unique character, therefore, the surfactant in the present embodiment is preferably high molecular surfactant.

Step 203, according to described wafer characteristics data and described current lapping liquid configuration data, by macromolecule reference role point model, obtain the abrasive grains adsorbed state data corresponding with described current lapping liquid configuration data:

Obtaining the corresponding abrasive grains adsorbed state data of described and current lapping liquid configuration data according to current lapping liquid configuration data and wafer characteristics data, is to utilize macromolecule reference role point model (PRISM), and the method by numerical computations realizes.These abrasive grains adsorbed state data comprise some characterization values of spatial distribution between abrasive grains in the lapping liquid, surfactant molecule and the crystal column surface molecule.And in the present embodiment, to the sign of these three kinds of particles of abrasive grains, surfactant molecule and crystal column surface molecule in spatial distribution, realize by radial distribution function.

Radial distribution function can disclose the probability statistics feature between the active agent molecule deeply as " order parameter " of description system space structure, the strict solvation barrier potential effect that characterizes between abrasive grains, high molecular surfactant and the crystal column surface.Concentration by the control surface activating agent, distribution of charges etc. can form stablizes solid solvation space film, thereby prevents that abrasive grains from assembling to crystal column surface.Therefore, the distribution character of radial distribution function can be used as the important indicator of crystal column surface particle adsorbed state.Usually, peak Distribution according to radial distribution function, can judge position and probability density that active agent molecule, abrasive grains etc. occur at crystal column surface, and size and the thickness of solvation film space structure, thereby judge that abrasive grains is at the adsorbed state of crystal column surface.The peak value of radial distribution function can reflect the power of intermolecular interaction, the thickness of solvation membrane structure and the size of intermolecular repulsive force, therefore, can judge according to these peak change features because the stable state of the abrasive grains absorption that barrier potential causes.In case the heterogeneous dispersion of lapping liquid changes, the solvation membrane structure changes thereupon, abrasive grains fluctuates to crystal column surface, marked change will take place in distributions such as the peak value size of system radial distribution function, density, the thermodynamic equilibrium state of original system stable dispersion changes, therefore, can characterize the adsorbed state that abrasive grains changes at crystal column surface by the peak change of analogue observation radial distribution function.In addition, radial distribution function by system, can also further obtain the solvation free energy of system, the solvation free energy also can reflect the power of intermolecular interaction, therefore, the variation by analogue observation system solvation free energy also can characterize the adsorbed state that abrasive grains changes at crystal column surface.

Based on above-mentioned principle, in the present embodiment, provide the specific embodiment of two kinds of steps 203.First kind of embodiment is to adopt between crystal column surface and surfactant molecule and peak height and the length of the radial distribution function between crystal column surface and abrasive grains, as abrasive grains adsorbed state data; Second kind of embodiment is to adopt the solvation free energy of grinding system as the adsorbed state data of abrasive grains.

Below in conjunction with above-mentioned explanation to abrasive grains adsorbed state data, describe two kinds of specific embodiment of step 203 in the present embodiment in detail.

First kind of embodiment flow process is as shown in Figure 3 finished, and idiographic flow comprises following step:

Step 301, according to the material of crystal column surface in the described wafer characteristics data, and kind, size, concentration and the distribution of charges of abrasive grains and kind, size, concentration and the distribution of charges of surfactant molecule in the described current lapping liquid configuration data, by the distribution function theory, obtain correlation function in the molecule of surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains;

Step 302, according to correlation function in the molecule of described surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains, find the solution macromolecule reference role point model integral equation, obtain the radial distribution function that reaches between crystal column surface and surfactant molecule between crystal column surface and abrasive grains;

The peak height of the radial distribution function between step 303, the peak height of obtaining radial distribution function between described crystal column surface and surfactant molecule and length and crystal column surface and abrasive grains and length are as the abrasive grains adsorbed state data under the current configuration.

Second kind of embodiment as shown in Figure 4, idiographic flow comprises the steps:

Step 401, according to the material of crystal column surface in the described wafer characteristics data, and kind, size, concentration and the distribution of charges of abrasive grains and surfactant molecule in the described current lapping liquid configuration data, by the distribution function theory, obtain correlation function in the molecule of surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains;

Step 402, according to correlation function in the molecule of described surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains, find the solution macromolecule reference role point model integral equation, obtain between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the radial distribution function between crystal column surface and abrasive grains;

Step 403, according between described surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the radial distribution function between crystal column surface and abrasive grains, obtain the solvation free energy of current grinding system;

Step 404, obtain the solvation free energy of current grinding system as the abrasive grains adsorbed state data under the current configuration.

Need to prove in step 302 and step 402, when finding the solution macromolecule reference role point model integral equation, multiple method for solving is arranged.To find the solution difficulty in order reducing, to improve computational efficiency, when finding the solution, described macromolecule reference role point model theoretical equation can be converted into the Fourier matrix form, and adopt the Fourier conversion to find the solution in conjunction with the numerical method of revising direct iteration subspace.

In addition, for those skilled in the art have clearer understanding for finding the solution the process that the PRISM integral equation obtains each radial distribution function in step 302 and the step 402, below step 302 and step 402 are described in further details.

Need to prove, in the following detailed description, be that example describes with preferred high molecular surfactant all; For little molecular surface active agent, the implementation procedure of step 302 and step 402 equally also can be suitable for following explanation, but because its realization is more simple, therefore repeats no more.

Before describing step 302 and step 402 in detail, below earlier the solution of PRISM integral equation is made a detailed explanation.In the following solution procedure, in order to take into full account structural parameters and the energy parameter between different groups, the generator matrix method of introducing the Conformation Statistics of Polymer Chain theory is obtained in the molecule of high molecular surfactant correlation function (calling correlation function in the high molecular surfactant molecule in the following text) between group.PRISM solution as shown in Figure 5, idiographic flow is as follows:

Finding the solution of step 501, the interior correlation function of high molecular surfactant molecule:

When finding the solution the PRISM integral equation, considered the not isoplastic locus of high molecular surfactant in the present embodiment, comprise group diameter, bond distance, bond angle, the group interphase interaction, comprise Fan Dehuali, bond energy, distortional energy, set up correlation function in the surfactant molecule with the generator matrix method.

The PRISM theoretical model of finding the solution mainly is to set up in the polymer molecule and the association between the intermolecular different correlation function, can be expressed as following integral equation form:

h(r)=∫dr'∫dr''ω(|r-r'|)C(|r'-r''|)[ω(r'')+ρh(r'')] (1)

In the above-mentioned formula (1), ρ can obtain by surfactant concentrations in the current lapping liquid configuration data, and C (r) is directly related function, and ω (r) is correlation function in the molecule, and h (r) is the total correlation function, and radial distribution function is: g (r)=h (r)+1.

For conveniently finding the solution the PRISM integral equation of formula (1), usually formula (1) is converted into the Fourier matrix form:

$\hat{h}\left(k\right)=\widehat{\mathrm{\ω}}\left(k\right)\hat{C}\left(k\right)[\widehat{\mathrm{\ω}}\left(k\right)+\mathrm{\ρ}\hat{h}\left(k\right)]---\left(2\right)$

Be solving equation formula (2), at first need initial ω (r) as input.According to the distribution function theory, correlation function can be expressed as between molecule interior any two group α, the γ:

${\widehat{\mathrm{\ω}}}_{\mathrm{\α\γ}}\left(k\right)\frac{\sin \left(B_{\mathrm{\α\γ}}k\right)}{B_{\mathrm{\α\γ}}k}{e}^{-A_{\mathrm{\α\γ}}^2{k}^2}---\left(3\right)$

In the formula (3):

$A_{\mathrm{\&alpha;\&gamma;}}^2=<r_{\mathrm{\&alpha;\&gamma;}}^2>(1-C_{\mathrm{\&alpha;\&gamma;}})/6;B_{\mathrm{\&alpha;\&gamma;}}^2=C_{\mathrm{\&alpha;\&gamma;}},<r_{\mathrm{\&alpha;\&gamma;}}^2>;C_{\mathrm{\&alpha;\&gamma;}}^2=\frac{1}{2}(5-3\frac{<r_{\mathrm{\&alpha;\&gamma;}}^4>}{{<r_{\mathrm{\&alpha;\&gamma;}}^2>}^2})---\left(4\right)$

In the above-mentioned formula (4),

With

Be respectively second moment and Fourth-order moment.In the present embodiment, according to the kind of surfactant in the current lapping liquid configuration data, can obtain by the generator matrix method that adopts the Conformation Statistics of Polymer Chain theory

With Thereby the interior correlation function of the molecule between any group in the high molecular surfactant strand is calculated in through type (3) and (4) (k).

Step 502, introducing hyper-netted chain, find the solution the PRISM equation:

The hyper-netted chain of introducing is as follows:

h _αγ(r)=exp[-u _αγ(r)/kT+h _αγ(r)-C _αγ(r)]-1 (5)

In the above-mentioned formula (5), u _{α γ}(r) be the intermolecular potential energy function, concrete form is as follows:

$u_{\mathrm{\&alpha;\&gamma;}}\left(r\right)={\mathrm{\&epsiv;}}_{\mathrm{\&alpha;\&gamma;}}[{\left(\frac{{\mathrm{\&sigma;}}_{\mathrm{\&alpha;\&gamma;}}}{r}\right)}^{12}-2{\left(\frac{{\mathrm{\&sigma;}}_{\mathrm{\&alpha;\&gamma;}}}{r}\right)}^6]+\frac{q_{\mathrm{\&alpha;}}{q}_{\mathrm{\&gamma;}}}{r}---\left(6\right)$

In the above-mentioned formula (6), ε is the chromatic dispersion energy, σ is the group diameter, and q is the group electric charge, all can be according to the acquisitions such as kind, group energy parameter (can be determined by kind), temperature and distribution of charges of abrasive grains and surfactant molecule in the current lapping liquid configuration data.

Behind the introduction-type (5), correlation function in the molecule that formula (3) and (4) are obtained

(k) in the integral equation of substitution formula (1), with the formula (1) and formula (5) simultaneous that obtain, the PRISM equation be can find the solution again, system each directly related function and radial distribution function obtained.

Because above-mentioned equation is the nonlinear integral equation group, therefore, find the solution in conjunction with numerical methods such as revising direct iteration subspace by adopting the Fourier conversion, can improve computational efficiency greatly.

In addition, PRISM Solution of Integral Equations shown in Figure 5 is a complete solution procedure, but solves the process of radial distribution function for the PRISM equation between concrete different molecular, can all comprise among Fig. 5 institute in steps.

After the solution of PRISM equation in the step 302 having been done detailed description, describe in detail below and utilize PRISM equations system method shown in Figure 6 to come the idiographic flow of performing step 302 and step 402.In the present embodiment, based on PRISM equations system method shown in Figure 5, consider the interaction of abrasive grains, surfactant molecule and crystal column surface, in step 302 and step 402, use following PRISM equation:

h _ss(k)=ω _s(k)C _ss(k)ω _s(k)+ρ _sω _s(k)C _ss(k)h _ss(k) (7)

h _w's(k)=ω _w'(k)C _w's(k)ω _s(k)+ρ _sω _w'(k)C _w's(k)h _ss(k) (8)

h _wa(k)=ω _w(k)C _wa(k)ω _a(k)+ρ _sω _w(k)C _wa(k)h _sa(k) (9)

In above-mentioned formula (7)～(9); subscript s presentation surface active agent molecule; subscript w ' expression abrasive grains or crystal column surface; subscript w represents crystal column surface; subscript a represents abrasive grains; between subscript ss presentation surface active agent molecule, subscript w ' s represents between abrasive grains and surfactant molecule or between surfactant molecule and crystal column surface, subscript wa represents between crystal column surface and abrasive grains.

Based on the PRISM equation of formula (7)～(9), the idiographic flow of step 302 and step 402 comprises the steps: as shown in Figure 6

Step 601, obtain the intermolecular calculating parameter of high molecular surfactant:

According to current lapping liquid configuration data, correlation function in the molecule that molecular geometry and the energy parameter by surfactant obtains surfactant; By group energy parameter, temperature and the distribution of charges etc. of surfactant molecule, obtain the intermolecular potential energy of surfactant; By surfactant concentrations, obtain the number density of molecule ρ of surfactant.

Step 602, obtain the calculating parameter between abrasive grains and surfactant molecule:

According to current lapping liquid configuration data, by group energy parameter, temperature and the distribution of charges etc. of abrasive grains and surfactant molecule, obtain the intermolecular potential energy of abrasive grains and surfactant; By the concentration of abrasive grains, obtain the number density of molecule ρ of abrasive grains.

Step 603, obtain the calculating parameter between crystal column surface and surfactant molecule:

According to current lapping liquid configuration data and wafer characteristics data, by group energy parameter, temperature and the distribution of charges etc. of wafer and surfactant molecule, obtain the intermolecular potential energy of crystal column surface and surfactant.

Step 604, obtain the calculating parameter between crystal column surface and abrasive grains:

According to current lapping liquid configuration data and wafer characteristics data, by group energy parameter, temperature and the distribution of charges etc. of wafer and abrasive grains, obtain the intermolecular potential energy of crystal column surface and abrasive grains.

Step 605, obtain between the surfactant molecule, between abrasive grains and the surfactant molecule, between crystal column surface and the surfactant molecule and the radial distribution function between crystal column surface and the abrasive grains:

According to the calculating parameter that above-mentioned steps 601～step 604 obtains,, find the solution (7) formula according to step 501～step 502, can get the radial distribution function between the surfactant molecule; Again (8) formula of bringing into of the radial distribution function between active agent molecule is found the solution, bring the result of calculation of (8) formula into (9) formula then, in the solution procedure of (8), (9) formula, need to do and three-dimensional calculate fast, with obtain between abrasive grains and the surfactant molecule, between crystal column surface and the surfactant molecule and the three-dimensional radial distribution function between crystal column surface and the abrasive grains.

Need to prove, for second kind of embodiment shown in Figure 4, adopt the mode of above-mentioned Fig. 5 and Fig. 6 to come completing steps 402, also can obtain each corresponding directly related function when obtaining each radial distribution function.After step 402 was complete, the solvation free energy that corresponding step 403 is obtained current grinding system can calculate by following formula:

$\mathrm{\&Delta;\&mu;}=\underset{\mathrm{\&alpha;},\mathrm{\&beta;}}{\mathrm{\&Sigma;}}\&Integral;\mathrm{dr}\&CenterDot;{\mathrm{\&rho;}}_{\mathrm{\&alpha;},\mathrm{\&beta;}}[\frac{1}{2}{h}_{\mathrm{\&alpha;},\mathrm{\&beta;}}{\left(r\right)}^2-C_{\mathrm{\&alpha;},\mathrm{\&beta;}}\left(r\right)-\frac{1}{2}{h}_{\mathrm{\&alpha;},\mathrm{\&beta;}}\left(r\right)\&CenterDot;C_{\mathrm{\&alpha;},\mathrm{\&beta;}}\left(r\right)]---\left(10\right)$

In the above-mentioned formula (10), Δ μ is the solvation free energy, h _{α, β}(r) be each radial distribution function, C _{α, β}(r) be each directly related function, ρ _{α, β}Be each concentration.

Then return Fig. 2, after step 203 is complete, execution in step 204.

Step 204, judge whether described abrasive grains adsorbed state data satisfy physical absorption state standard, if not, enter step 205, if enter step 206:

Because in the present embodiment, step 203 has two kinds of embodiments, first kind be with between surfactant molecule and the peak height of the radial distribution function between crystal column surface and abrasive grains and width as abrasive grains adsorbed state data, second kind is that solvation free energy with grinding system is as abrasive grains adsorbed state data.So, present embodiment also provides corresponding embodiment in step 204, whether the abrasive grains adsorbed state data of judging two kinds of embodiments respectively satisfy corresponding physical adsorption criteria separately, judge with this whether the configuration of surfactant in the current lapping liquid can make abrasive grains be in physical absorption at crystal column surface, thereby make the easier cleaning of particle of crystal column surface behind the chemical mechanical milling tech.

In the corresponding step 203 with between surfactant molecule and the peak height of the radial distribution function between crystal column surface and abrasive grains and width as the embodiment of abrasive grains adsorbed state data, the specific embodiment of two kinds of steps 204 is provided in the present embodiment, has been respectively:

First kind of embodiment is to judge with the peak value length of the radial distribution function between crystal column surface and surfactant molecule whether abrasive grains is in the physical absorption state at crystal column surface, be specially: judge that whether the peak height of the radial distribution function between crystal column surface described in the described abrasive grains adsorbed state data and surfactant molecule is greater than default peak height threshold value, if not, enter step 205, if enter step 206.

The more high explanation intermolecular interaction of the peak value of radial distribution function is more strong, and the intermolecular interaction between crystal column surface and surfactant molecule is more strong, the surfactant molecule that the crystal column surface combination then is described is more many, abrasive grains just more is not easy to form chemisorbed with crystal column surface, thereby rests on the physical absorption state.Therefore, set a threshold value, make the peak height of the radial distribution function between crystal column surface and surfactant molecule remain on this more than threshold value, then the configuration of the lapping liquid of this radial distribution function correspondence just can make abrasive grains be in the physical absorption state at crystal column surface.

Second kind of embodiment is to judge with the peak value length of the radial distribution function between crystal column surface and abrasive grains whether abrasive grains is in the physical absorption state at crystal column surface, this mode is specially: judge that whether the peak value length of the radial distribution function between crystal column surface described in the described abrasive grains adsorbed state data and abrasive grains is greater than default peak value length threshold value, if not, enter step 205, if enter step 206.

Because the intermolecular repulsive force of peak value explanation more far away of radial distribution function is more big, and the intermolecular repulsive force between crystal column surface and abrasive grains is more big, illustrates that then the suction-operated of abrasive grains and crystal column surface is more weak, the more easy physical absorption state that is in.Therefore, set a threshold value, make that the peak value length of radial distribution function reaches this more than threshold value between crystal column surface and abrasive grains, then the configuration of the lapping liquid of this radial distribution function correspondence just can make abrasive grains be in the physical absorption state at crystal column surface.

In the corresponding step 203 with the solvation free energy of the grinding system embodiment as abrasive grains adsorbed state data, a kind of specific embodiment of step 204 is provided in the present embodiment, be specially: judge that whether the solvation free energy of current grinding system in the described abrasive grains adsorbed state data is less than default free energy threshold value, if not, enter step 205, if enter step 206.

Because the solvation free energy of grinding system is more low, the interaction in the explanation system between active agent molecule and crystal column surface and abrasive grains is more stable, and also, abrasive grains more is difficult to form chemisorbed at crystal column surface, and is in the physical absorption state always.Therefore, set a threshold value, make the solvation free energy of grinding system at this below threshold value, then the configuration of the lapping liquid of this solvation free energy correspondence just can make abrasive grains be in the physical absorption state at crystal column surface.

In three above embodiments, default peak height threshold value, length threshold value and free energy threshold value, can be to preestablish a fixed value, also can preset a threshold data storehouse that stores a plurality of threshold values of corresponding process conditions preservation, call corresponding threshold according to the selected process conditions of step 201 then.

In addition, need to prove that the judgement in the step 204 generally is not that a peak feature value only choosing a radial distribution function as three above-mentioned embodiments is judged, perhaps only judge with the solvation free energy.Usually, when judging the adsorbed state of abrasive grains at crystal column surface, need take all factors into consideration three characteristic values of peak value of radial distribution function between three kinds of different microcosmic particles and the solvation free energy of system, need judge whether this characteristic value meets the demands at each characteristic value, and the judged result of all characteristic values is done the comprehensive statistics analysis, and whether the abrasive grains that finally draws this lapping liquid system is in the judgement of physical absorption state at crystal column surface.

After step 204 is finished, if judged result is that then execution in step 205.

Step 205, the described current lapping liquid configuration data of adjustment, and the lapping liquid configuration data after will adjusting is as described current lapping liquid configuration data; Enter step 203.

The concrete grammar of adjusting, can use following mode to realize: the kind of corresponding high molecular surfactant, size, concentration and distribution of charges arrange corresponding database respectively; When adjusting, choose the next data of current lapping liquid configuration data in the database, as the data after adjusting; As there not being this current data in the database, then with the data of first data decimation in the database after as adjustment, and will these current data after choosing save as first data in the database.As to the adjustment process of the kind of surfactant can for: set in advance a kinds of surfactants database, when needs are adjusted activating agent kind time-like, then choose the next kind data of the kind data in corresponding this current lapping liquid configuration data in the kinds of surfactants database, as the kind data after adjusting.

Because abrasive grains is realized by add surfactant in lapping liquid in the control of the adsorbed state of crystal column surface, so, the relevant configuration data of general adjustment form surface-active agent when adjusting current lapping liquid configuration data.For these reasons, step 205 can realize by following embodiment in the present embodiment: kind, size, concentration and the distribution of charges of the abrasive grains in the current lapping liquid configuration data are fixed, adjust kind, size, concentration and the distribution of charges of the surfactant in the current lapping liquid configuration data, and the lapping liquid configuration data after will adjusting is as described current lapping liquid configuration data; Enter step 203.

Need to prove, owing in the current lapping liquid configuration data that needs to adjust in the step 205 a plurality of data are arranged, though return the adsorbed state that step 203 reanalyses abrasive grains again after can simultaneously all data all having been adjusted, but this method can not all be optimized each data in the current lapping liquid configuration, so and impracticable.And adopt the method that each data of current lapping liquid configuration data are all adjusted separately all to be optimized each data in the current lapping liquid configuration data.When adjusting separately, it is constant to fix other data, namely enters the adsorbed state that step 203 reanalyses abrasive grains after adjusting separately, after these data have satisfied physical absorption state standard, adjusts the next data in the current lapping liquid configuration data again.

Below in conjunction with Fig. 7, describe a kind of embodiment that adopts the step 205 that each data in the current lapping liquid configuration data are adjusted separately in detail:

The kind of step 701, adjustment high molecular surfactant: the configuration data of the concentration of fixed surface activating agent, size and distribution of charges and abrasive grains, the kind of adjustment form surface-active agent, return step 203 analysis again, judged by step 204, as do not meet physical absorption state standard, then continue the kind of adjustment form surface-active agent, satisfy physical absorption state standard until step 204 judgement, the kind of the surfactant that obtains as the kinds of surfactants of optimizing, is entered step 702.Wherein, the configuration data of abrasive grains comprises kind, concentration, size and the distribution of charges of abrasive grains; This configuration data can be by the selected abrasive grains configuration of experience according to process conditions.

The concentration of step 702, adjustment high molecular surfactant: the kind of the surfactant after the size of fixed surface activating agent and distribution of charges, abrasive grains configuration data and the optimization, adjust surfactant concentrations, return step 203 analysis again, judged by step 204, as do not meet physical absorption state standard, then continue to adjust surfactant concentrations, satisfy physical absorption state standard until step 204 judgement, the surfactant concentrations that obtains as the surfactant concentration of optimizing, is entered step 703.

The size of step 703, adjustment high molecular surfactant: kind, the concentration of the surfactant after the distribution of charges of fixed surface activating agent, abrasive grains configuration data and the optimization, the size of adjustment form surface-active agent, return step 203 analysis again, judged by step 204, as do not meet physical absorption state standard, then continue the size of adjustment form surface-active agent, satisfy physical absorption state standard until step 204 judgement, the size of the surfactant that obtains as the surfactant size of optimizing, is entered step 704.

Step 704, adjust the distribution of charges of high molecular surfactant: fixedly kind, concentration and the size of the surfactant after abrasive grains configuration data and the optimization, the distribution of charges of adjustment form surface-active agent, return step 203 analysis again, judged by step 204, as do not meet physical absorption state standard, then continue the distribution of charges of adjustment form surface-active agent, satisfy physical absorption state standard until step 204 judgement, the distribution of charges of the surfactant that obtains as the surfactant distribution of charges of optimizing, is entered step 705.

Step 705, with the surfactant configuration data in the current lapping liquid configuration data, be updated to kind, concentration, size and the distribution of charges of the surfactant after the optimization.

Embodiment at shown in Figure 7 need to prove, step 701 to step 704 is not must be according to order shown in Figure 7, can be without limits to the order that each data are adjusted.

Then return Fig. 2, after step 205 is finished, enter step 203 again and analyze, through the judgement of step 204, if judged result is for being to enter step 206.

Step 206, with described current lapping liquid configuration data as lapping liquid configuration optimization data, and the lapping liquid that utilizes lapping liquid configuration optimization data configuration to be optimized.

Process step 201 is to the optimization of 205 pairs of lapping liquid configuration datas, the current lapping liquid configuration data that obtains meets physical absorption state standard-required, carry out the configuration of lapping liquid high molecular surfactant with current lapping liquid configuration data, and lapping liquid is used for chemical mechanical milling tech, abrasive grains is in the physical absorption state at crystal column surface, after technology was finished, abrasive grains was removed from crystal column surface easily.

Except above-mentioned steps 201 to 206, in order no longer same process conditions to be done the process of the optimization lapping liquid configuration of repetition, can also be after step 205 executes in the present embodiment, carry out following step 207: with lapping liquid configuration optimization data, be stored in the lapping liquid configuration database with the corresponding relation of described selected process conditions, the abrasive grains adsorbed state data that described lapping liquid is distributed the data correspondence rationally satisfy described physical absorption state.

After the execution of step 207, when running into the process conditions of having optimized the lapping liquid configuration again, step 202 can directly be obtained the lapping liquid configuration data of having optimized in the lapping liquid configuration database, do not need execution in step 203 to 205, directly execution in step 206 is carried out cmp again.

In addition, present embodiment can also comprise after step 206: utilize the lapping liquid of described optimization under the process conditions of described selected cmp, wafer to be ground, and after grinding the cleaning wafer surface to remove the abrasive grains of crystal column surface.With this, realize utilizing the lapping liquid after the optimization to carry out cmp processing.

Technical scheme by present embodiment, obtain wafer characteristics data and current lapping liquid configuration data according to selected process conditions, utilize macromolecule reference point model to the abrasive grains in the lapping liquid, the spatial distribution of surfactant and crystal column surface characterizes, thereby analyze the abrasive grains adsorbed state data that obtain under the current lapping liquid configuration, judge whether to satisfy physical absorption state standard with these abrasive grains adsorbed state data, according to judged result current lapping liquid configuration data is adjusted again, be met the target lapping liquid configuration data of physical absorption state standard, to satisfy the current lapping liquid configuration data of physical absorption state standard at last as lapping liquid configuration optimization data, and the lapping liquid that utilizes this lapping liquid configuration optimization data configuration to be optimized.Like this, adjustment and the optimization of chemical-mechanical grinding liquid configuration, can utilize macromolecule reference role point model to differentiate the lapping liquid of current configuration when grinding wafer, whether the adsorbed state of abrasive grains on crystal column surface is in the physical absorption state of easy desorb, thereby, the optimizing process of lapping liquid configuration is simplified, and is adsorbed on after guaranteeing to grind when abrasive grains on the crystal column surface is easy to remove, and process optimization cost and the cycle of chemical-mechanical grinding liquid all are minimized.

Need to prove, in this article, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thereby make and comprise that process, method, article or the equipment of a series of key elements not only comprise those key elements, but also comprise other key elements of clearly not listing, or also be included as the intrinsic key element of this process, method, article or equipment.Do not having under the situation of more restrictions, the key element that is limited by statement " comprising ... ", and be not precluded within process, method, article or the equipment that comprises described key element and also have other identical element.

The above only is preferred embodiment of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (10)

1. the method for a chemical-mechanical grinding liquid configuration optimization is characterized in that, described method comprises the steps:

Steps A: the process conditions of selected cmp;

Step B: according to selected process conditions, material when obtaining crystal column surface and grinding is as the wafer characteristics data, and kind, size, concentration and the distribution of charges of obtaining kind, size, concentration and the distribution of charges of abrasive grains in the default lapping liquid and surfactant are as current lapping liquid configuration data;

Step C: according to described wafer characteristics data and described current lapping liquid configuration data, by macromolecule reference role point model, obtain the abrasive grains adsorbed state data corresponding with described current lapping liquid configuration data;

Step D: judge that whether described abrasive grains adsorbed state data satisfy physical absorption state standard, if not, enter step e, if enter step F;

Step e: adjust described current lapping liquid configuration data, and the lapping liquid configuration data after will adjusting is as described current lapping liquid configuration data; Enter step C;

Step F: with described current lapping liquid configuration data as lapping liquid configuration optimization data, and the lapping liquid that utilizes lapping liquid configuration optimization data configuration to be optimized.

2. method according to claim 1 is characterized in that, described step C comprises:

Step C11: according to the material of crystal column surface in the described wafer characteristics data, and kind, size, concentration and the distribution of charges of abrasive grains and kind, size, concentration and the distribution of charges of surfactant molecule in the described current lapping liquid configuration data, by the distribution function theory, obtain correlation function in the molecule of surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains;

Step C12: according to correlation function in the molecule of described surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains, find the solution macromolecule reference role point model integral equation, obtain the radial distribution function that reaches between crystal column surface and surfactant molecule between crystal column surface and abrasive grains;

Step C13: obtain the peak height of radial distribution function between the peak height of radial distribution function between described crystal column surface and surfactant molecule and length and crystal column surface and abrasive grains and length as the abrasive grains adsorbed state data under the current configuration.

3. method according to claim 2, it is characterized in that, described step D comprises: judge that whether the peak height of the radial distribution function between crystal column surface described in the described abrasive grains adsorbed state data and surfactant molecule is greater than default peak height threshold value, if not, enter step e, if enter step F.

4. method according to claim 2, it is characterized in that, described step D comprises: judge that whether the peak value length of the radial distribution function between crystal column surface described in the described lapping liquid particle adsorbed state data and abrasive grains is greater than default peak value length threshold value, if not, enter step e, if enter step F.

5. method according to claim 1 is characterized in that, described step C comprises:

Step C21: according to the material of crystal column surface in the described wafer characteristics data, and kind, size, concentration and the distribution of charges of abrasive grains and kind, size, concentration and the distribution of charges of surfactant molecule in the described current lapping liquid configuration data, by the distribution function theory, obtain correlation function in the molecule of surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains;

Step C22: according to correlation function in the molecule of described surfactant, crystal column surface and abrasive grains, and between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the intermolecular potential energy function between crystal column surface and abrasive grains, find the solution macromolecule reference role point model integral equation, obtain between surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the radial distribution function between crystal column surface and abrasive grains;

Step C23: according between described surfactant molecule, between abrasive grains and surfactant molecule, between crystal column surface and surfactant molecule and the radial distribution function between crystal column surface and abrasive grains, obtain the solvation free energy of current grinding system;

Step C24: obtain the solvation free energy of current grinding system as the abrasive grains adsorbed state data under the current configuration.

6. method according to claim 5 is characterized in that, described step D comprises: judge that whether the solvation free energy of current grinding system in the described abrasive grains adsorbed state data is less than default free energy threshold value, if not, enter step e, if enter step F.

7. according to any described method of claim 2-6, it is characterized in that, the described theoretical integral equation of macromolecule reference role point model of finding the solution comprises: described macromolecule reference role point model integral equation is converted into the Fourier matrix form, and adopts the Fourier conversion to find the solution in conjunction with the numerical method of revising direct iteration subspace.

8. method according to claim 1, it is characterized in that, described step e comprises: kind, size, concentration and the distribution of charges of the abrasive grains in the current lapping liquid configuration data are fixed, adjust kind, size, concentration and the distribution of charges of the surfactant in the current lapping liquid configuration data, and the lapping liquid configuration data after will adjusting is as described current lapping liquid configuration data; Enter step C.

9. method according to claim 1, it is characterized in that, also comprise after the step F: with lapping liquid configuration optimization data, be stored in the lapping liquid configuration database with the corresponding relation of described selected process conditions, the abrasive grains adsorbed state data that described lapping liquid is distributed the data correspondence rationally satisfy described physical absorption state.

10. method according to claim 1, it is characterized in that, also comprise after the step F: utilize the lapping liquid of described optimization under the process conditions of described selected cmp, wafer to be ground, and after grinding the cleaning wafer surface stage remove the abrasive grains of crystal column surface.

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