CN105046066A - AlGaN/GaN HETM small-signal model and parameter extraction method thereof - Google Patents

Abstract

The invention provides an AlGaN/GaN HETM small-signal model and a parameter extraction method thereof. The small-signal model comprises a parasitic part and an intrinsic part; and the intrinsic part comprises intrinsic capacitors including Cgd, Cgs and Cds, a gate-source leakage resistor Rgsf, a gate-drain leakage resistor Rgdf, a channel resistor Ri, a source-drain resistor Rds and a transconductor Gm. According to the invention, on the basis of the original AlGaN/GaN HETM small-signal model, the gate-drain leakage resistor Rgsf applicable to representing electric leakage between the gate and the drain and the gate-source leakage resistor Rgdf applicable to representing electric leakage between the gate and the source are additionally arranged; because unavoidable leakage current exists below the gate and at two sides of the gate when a device is in a normal working state, the characteristics of the device can be reflected more precisely after the two components are added, and therefore, the accuracy rate of a device model is improved.

Description

AlGaN/GaN HETM small-signal model and put forward ginseng method

Technical field

The invention belongs to technical field of integrated circuits, particularly relate to a kind of AlGaN/GaNHETM small-signal model and put forward ginseng method.

Background technology

In the whole flow process of microwave circuits, device model serves the crucial function served as bridge that technique, device and circuit design are connected effectively, and be able to the characteristic of device to be reflected to exactly in circuit, completing circuit simulation result, prediction circuit characteristic, evaluation circuits overall performance and yield rate.Accurate device small-signal model is that its corresponding large signal characteristic analysis provides necessary data, and is the important means of prediction device small signal S-parameters characteristic; The employing of accurate device large-signal model, simplifies the design procedure of radio frequency and microwave and millimeter wave power circuit to a certain extent, shortens the circuit lead time and has saved cost.In addition, after flow completes, extraction model parameter, by contrast, the data analyzed in different flow situation, can the parameter value of feedback device important physical technique, and monitor processing quality and process repeatability with this, and then the direction of guidance device piece optimization.As can be seen here, one all serves very important effect in small-signal model technique in the early stage, device and the circuit design in later stage accurately.

AlGaN/GaNHEMT (HighElectronMobilityTransistor, High Electron Mobility Transistor) developing history of device is relatively short, its model investigation achievement is also relatively less, and mainly continues to use the correlation model of the field effect transistors such as MESFET, MOSFET.But the charge carrier in AlGaN/GaNHEMT is the high concentration 2DEG (two-dimensional electron gas) be present in raceway groove, has a great difference with the principle of work of MESFET, MOSFET, the existence that error applied mechanically by model is can hardly be avoided.

Several researchers have proposed several model in recent years to realize and the electrical characteristics of HEMT device be reflected in circuit, Fig. 1 and Fig. 2 be at present conventional AlGaN/GaNHEMT small-signal model as shown in Figure 1 to Figure 2.The AlGaN/GaNHEMT small-signal model that Fig. 1 provides is by parasitic PAD electric capacity Cpg, Cpd and Cpgd, stray inductance Lg, Ld and Ls, dead resistance Rg, Rd and Rs, intrinsic capacity Cgd, Cgs and Cds, electric current input characterization unit Igs, Igd and Ids, source and drain resistance Rds, channel resistance Ri, the scattering that trap effect causes frequency to occur (comprises Rrf, Irf and Crf) and heat transmission unit (comprise thermal resistance Rth, the characterization unit Ith of thermal capacitance Cth and the input of sign heat transfer electric current) composition, the AlGaN/GaNHEMT small-signal model that Fig. 2 provides is made up of parasitic PAD electric capacity Cpg, Cpd and Cpgd, stray inductance Lg, Ld and Ls, dead resistance Rg, Rd and Rs, intrinsic capacity Cgd, Cgs and Cds, source and drain resistance Rds, channel resistance Ri and mutual conductance Gm.

Although the characteristic of AlGaN/GaNHEMT device can be reflected in circuit by these two kinds of models in Fig. 1 and Fig. 2 substantially, the model relative complex in Fig. 1, put forward ginseng consuming time; Meanwhile, the height of assessment HEMT device reliability, the size of grid leakage current is an index not allowing to ignore, and it affects the precision of model, but the feature of the not good characterizing device electric leakage of these two models.This has higher requirement to modeling work person.

Summary of the invention

The shortcoming of prior art in view of the above, the object of the present invention is to provide a kind of AlGaN/GaNHETM small-signal model and puies forward ginseng method, this reliability factor of device gate leakage current is taken into account, thus reflects device property more accurately.This invention can also monitor processing quality and process repeatability under grid, and then the direction of guidance device piece optimization.Meanwhile, also for the foundation of the large-signal model of device provides necessary basis.

For achieving the above object and other relevant objects, what the invention provides a kind of AlGaN/GaNHETM small-signal model puies forward ginseng method, described in put forward ginseng method and comprise;

1) measure the S parameter of peripheral open circuit, and S parameter is transformed into obtains Y parameter, obtain the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd according to Y parameter;

2) S parameter of peripheral open circuit is measured, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, obtains the numerical value of stray inductance Lg, Ls and Ld according to Z parameter;

3) S parameter of peripheral open circuit is measured, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, obtains the numerical value of dead resistance Rg, Rs and Rd according to Z parameter;

4) S parameter of AlGaN/GaNHETM device is measured, go embedding step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, step 2) the stray inductance Lg, Ls and Ld and the step 3 that obtain) the dead resistance Rg, Rs and Rd that obtain, obtain the intrinsic S parameter of inner parameter, the conversion of intrinsic S parameter is obtained Y parameter, the numerical value of intrinsic parameters intrinsic capacity Cgd, Cgs and Cds, channel resistance Ri, mutual conductance gm, mutual conductance delay factor τ, output admittance Gds and conductance Ggsf, Ggdf can be tried to achieve according to Y parameter.

As a kind of preferred version of the ginseng method of carrying of AlGaN/GaNHETM small-signal model of the present invention, described step 1) under low frequency, cut-off condition, measure the S parameter of peripheral open circuit; Described step 2) under the forward biased condition of low frequency, Vgs>Vth, Vds=0, measure the S parameter of peripheral open circuit; Described step 3) under high-frequency, cut-off condition, measure the S parameter of peripheral open circuit; Described step 4) under the forward biased condition of Vgs>Vpinch-off, Vds=0, measure the S parameter of AlGaN/GaNHETM device.

As a kind of preferred version of the ginseng method of carrying of AlGaN/GaNHETM small-signal model of the present invention, described step 1) in obtain the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd concrete grammar be:

S parameter conversion is obtained Y parameter, through being converted to following formula:

$\frac{\mathrm{Im}\left(Y_{11}\right)}{w}=C_{pg}+C_{pgd}+W\·(C_{gdo}+C_{gso})$

$\frac{\mathrm{Im}\left(Y_{22}\right)}{w}=C_{pd}+C_{pgd}+W\·(C_{gdo}+C_{dso})$

$-\frac{Im\left(Y_{12}\right)}{w}=C_{pgd}+W\·C_{gdo}$

Wherein, Cgdo, Cgso, Cdso are scale factor, and W is device grid width; According to the linear relationship of Y parameter imaginary part frequency response Im (Yij)/ω with device grid width W, the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd can be drawn respectively through the intercept of linear fit.

As a kind of preferred version of the ginseng method of carrying of AlGaN/GaNHETM small-signal model of the present invention, described step 2) in obtain stray inductance Lg, the concrete grammar of numerical value of Ls and Ld is: the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, and the imaginary part of Z parameter and ω being divided by directly to obtain the numerical value of stray inductance Lg, Ls and Ld.

As a kind of preferred version of the ginseng method of carrying of AlGaN/GaNHETM small-signal model of the present invention, described step 3) in obtain dead resistance Rg, the concrete grammar of numerical value of Rs and Rd is: the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, directly can obtain the numerical value of dead resistance Rg, Rs and Rd according to the real part of Z parameter.

As a kind of preferred version of the ginseng method of carrying of AlGaN/GaNHETM small-signal model of the present invention, described step 4) in obtain intrinsic parameters intrinsic capacity Cgd, Cgs and Cds, channel resistance Ri, mutual conductance gm, mutual conductance delay factor τ, output admittance Gds and conductance Ggsf, Ggdf the concrete grammar of numerical value be: the conversion of intrinsic S parameter is obtained Y parameter, obtains following formula:

$Y_{11}=\frac{1}{R_i+\frac{1}{G_{gsf}+{\mathrm{jwC}}_{gs}}}+\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

$Y_{12}=-\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

${Y_2}_1=\frac{g_m{e}^{-jw\mathrm{\τ}}}{R_i{G}_{gsf}+{\mathrm{jwC}}_{gs}{R}_i+1}-\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

${Y_2}_2=G_{ds}+\frac{1}{\frac{1}{G_{gdf}+jw{\text{C}}_{gd}}}+jw{\text{C}}_{ds}$

Above-mentioned formula is carried out simplify processes and obtains Ygs, Ygd, Ygm and Yds:

$Y_{gs}=Y_{11}+Y_{12}=\frac{1}{R_i+\frac{1}{G_{gsf}+jw{\text{C}}_{gs}}}=\frac{G_{gsf}+jw{\text{C}}_{gs}}{1+R_i{G}_{gsf}+{\mathrm{jwR}}_i{C}_{gs}}$

Y _gd＝-Y ₁₂＝G _gdf+jwC _gd

$Y_{gm}=Y_{21}-Y_{12}=\frac{g_m{e}^{-jw\mathrm{\τ}}}{R_i{G}_{gsf}+{\mathrm{jwC}}_{gs}+1}$

Y _ds＝Y _i,22+Y _i,12＝G _ds+jwC _ds

Definition: $A=\frac{|Y_{gs}{|}^2}{\mathrm{Im}\[Y_{gs}\]}=\frac{{G_{gsf}}^2}{{\mathrm{wC}}_{gs}}+{\mathrm{wC}}_{gs}$

$B=\frac{Y_{gs}}{\mathrm{Im}\[Y_{gs}\]}=\frac{G_{gsf}(1+R_i{G}_{gsf})}{{\mathrm{wC}}_{gs}}+{\mathrm{wR}}_i{C}_{gs}-j$

$C={\left|\frac{Y_{gs}}{Y_{gm}}\right|}^2={\left(\frac{G_{gsf}}{g_m}\right)}^2+{\left(\frac{C_{gs}}{g_m}\right)}^2{w}^2$

$D=(G_{gsf}+{\mathrm{jwC}}_{gs})\frac{Y_{gm}}{Y_{gs}}=g_m{e}^{-jw\mathrm{\τ}}$

To ω ²~ A ω curve carries out linear fit can obtain Cgs; In conjunction with the Cgs obtained, to ω B ~ ω ²curve carries out linear fit can obtain Ri; Real part according to Ygs can determine Ggsf; According to formula Y _gd=-Y ₁₂=G _gdf+ jwC _gdmiddle plural corresponding relation can obtain Cgd and Ggdf; In conjunction with the Cgs obtained, to ω ²~ C curve carries out linear fit can obtain gm; Linear fit is carried out to ω ~ D curve and can obtain τ; According to formula Y _ds=Y _{i, 22}+ Y _{i, 12}=G _ds+ jwC _dsthe corresponding relation of middle real and imaginary part can obtain Gds and Cds.

The present invention also provides a kind of AlGaN/GaNHETM small-signal model, and described AlGaN/GaNHETM small-signal model comprises spurious portion and intrinsic part; Described intrinsic part comprises the grid leak bleeder resistance Rgdf that is suitable for characterizing and leaks electricity between grid leak and is suitable for characterizing the grid source bleeder resistance Rgsf leaked electricity between grid source.

As a kind of preferred version of AlGaN/GaNHETM small-signal model of the present invention, described intrinsic part comprises intrinsic capacity Cgd, Cgs and Cds, grid source bleeder resistance Rgsf, grid leak bleeder resistance Rgdf, channel resistance Ri, source and drain resistance Rds and mutual conductance Gm; Wherein,

Described intrinsic capacity Cgs connects to form cascaded structure with after the bleeder resistance Rgsf parallel connection of described grid source with described channel resistance Ri;

Described intrinsic capacity Cds connects to form cascaded structure with after described source and drain resistance Rds and described mutual conductance Gm parallel connection with described intrinsic capacity Cgd, and described grid leak bleeder resistance Rgdf is in parallel with described intrinsic capacity Cgd;

The cascaded structure that described intrinsic capacity Cds, described source and drain resistance Rds, described mutual conductance Gm and described intrinsic capacity Cgd are formed and the tandem construction parallel that described intrinsic capacity Cgs, described grid source bleeder resistance Rgsf and described channel resistance Ri are formed.

As a kind of preferred version of AlGaN/GaNHETM small-signal model of the present invention, described spurious portion comprises parasitic PAD electric capacity Cpg, Cpd and Cpgd, stray inductance Lg, Ld and Ls, dead resistance Rg, Rd and Rs; Wherein,

Described stray inductance Lg connects to form cascaded structure with described dead resistance Rg, cascaded structure one end that described stray inductance Lg and described dead resistance Rg is formed is connected to one end of described parasitic PAD electric capacity Cpg, and the other end is connected between described intrinsic capacity Cgd and Cgs; The other end ground connection of described parasitic PAD electric capacity Cpg;

Described stray inductance Ld connects to form cascaded structure with described dead resistance Rd, cascaded structure one end that described stray inductance Ld and described dead resistance Rd is formed is connected to one end of described parasitic PAD electric capacity Cpd, and the other end is connected between described intrinsic capacity Cgd and Cds; The other end ground connection of described parasitic PAD electric capacity Cpd;

Described parasitic PAD electric capacity Cpgd one end is connected to the cascaded structure of described stray inductance Lg and described dead resistance Rg formation and the link of described parasitic PAD electric capacity Cpg, and the other end is connected to the cascaded structure of described stray inductance Ld and described dead resistance Rd formation and the link of described parasitic PAD electric capacity Cpd;

Described stray inductance Ls connects to form cascaded structure with described dead resistance Rs, and cascaded structure one end that described stray inductance Ls and described dead resistance Rs is formed is connected to described channel resistance Ri one end away from described intrinsic capacity Cgs, other end ground connection.

As mentioned above, the invention provides a kind of AlGaN/GaNHETM small-signal model and put forward ginseng method, there is following beneficial effect: the present invention is on the basis of existing AlGaN/GaNHEMT small-signal model, set up the grid leak bleeder resistance Rgsf that is suitable for characterizing and leaks electricity between grid leak and be suitable for characterizing the grid source bleeder resistance Rgdf leaked electricity between grid source, due to device in normal operation, all there is inevitable leakage current under grid and grid both sides, therefore, after adding these two elements, device property can be reflected more accurately, improve device model accuracy rate.

Accompanying drawing explanation

Fig. 1 to Fig. 2 is shown as the circuit diagram of AlGaN/GaNHEMT small-signal model of the prior art.

Fig. 3 is shown as the structural representation of the device corresponding to AlGaN/GaNHETM small-signal model of the present invention.

Fig. 4 is shown as the equivalent circuit diagram of AlGaN/GaNHETM small-signal model of the present invention.

Fig. 5 is the process flow diagram putting forward ginseng method of AlGaN/GaNHETM small-signal model of the present invention.

What Fig. 6 was shown as AlGaN/GaNHETM small-signal model of the present invention to carry in ginseng method small-signal low frequency equivalent circuit diagram under cut-off condition.

What Fig. 7 was shown as AlGaN/GaNHETM small-signal model of the present invention to carry in ginseng method equivalent circuit diagram under forward biased condition.

What Fig. 8 was shown as AlGaN/GaNHETM small-signal model of the present invention to carry in ginseng method small-signal high frequency equivalent circuit figure under cut-off condition.

Embodiment

Below by way of specific instantiation, embodiments of the present invention are described, those skilled in the art the content disclosed by this instructions can understand other advantages of the present invention and effect easily.The present invention can also be implemented or be applied by embodiments different in addition, and the every details in this instructions also can based on different viewpoints and application, carries out various modification or change not deviating under spirit of the present invention.

Refer to Fig. 3 to Fig. 8.It should be noted that, the diagram provided in the present embodiment only illustrates basic conception of the present invention in a schematic way, though only show the assembly relevant with the present invention in diagram but not component count, shape and size when implementing according to reality is drawn, it is actual when implementing, and the kenel of each assembly, quantity and ratio can be a kind of change arbitrarily, and its assembly layout kenel also may be more complicated.

Refer to Fig. 3 to Fig. 4, the present embodiment provides a kind of AlGaN/GaNHETM small-signal model, as shown in Figure 3, instantiation is below exactly to adopting the equivalent electrical circuit of this device architecture and proposing the explanation that ginseng method carries out to device architecture corresponding to described AlGaN/GaNHETM small-signal model.The extraction of small-signal parameter is requisite link in the modeling of FET semiconductor devices, the accurate extraction of peripheral parasitic parameter can have influence on the accuracy of internal nonlinearity parameter, the extraction of small-signal model is the basis that large-signal model is set up, only guaranteed all small-signal parameter values are accurately reasonable, can set up large-signal model more accurately.

Fig. 4 is the equivalent circuit diagram of AlGaN/GaNHETM small-signal model, and by as shown in Figure 4, described AlGaN/GaNHETM small-signal model comprises spurious portion and intrinsic part; Described intrinsic part comprises the grid leak bleeder resistance Rgdf that is suitable for characterizing and leaks electricity between grid leak and is suitable for characterizing the grid source bleeder resistance Rgs leaked electricity between grid source.

Concrete, described intrinsic part comprises intrinsic capacity Cgd, Cgs and Cds, grid source bleeder resistance Rgsf, grid leak bleeder resistance Rgdf, channel resistance Ri, source and drain resistance Rds and mutual conductance Gm; Wherein, described intrinsic capacity Cgs connects to form cascaded structure with after the bleeder resistance Rgsf parallel connection of described grid source with described channel resistance Ri; Described intrinsic capacity Cds connects to form cascaded structure with after described source and drain resistance Rds and described mutual conductance Gm parallel connection with described intrinsic capacity Cgd, and described grid leak bleeder resistance Rgdf is in parallel with described intrinsic capacity Cgd; The cascaded structure that described intrinsic capacity Cds, described source and drain resistance Rds, described mutual conductance Gm and described intrinsic capacity Cgd are formed and the tandem construction parallel that described intrinsic capacity Cgs, described grid source bleeder resistance Rgsf and described channel resistance Ri are formed.

Concrete, described spurious portion comprises parasitic PAD electric capacity Cpg, Cpd and Cpgd, stray inductance Lg, Ld and Ls, dead resistance Rg, Rd and Rs; Wherein, described stray inductance Lg connects to form cascaded structure with described dead resistance Rg, cascaded structure one end that described stray inductance Lg and described dead resistance Rg is formed is connected to one end of described parasitic PAD electric capacity Cpg, and the other end is connected between described intrinsic capacity Cgd and Cgs; The other end ground connection of described parasitic PAD electric capacity Cpg; Described stray inductance Ld connects to form cascaded structure with described dead resistance Rd, cascaded structure one end that described stray inductance Ld and described dead resistance Rd is formed is connected to one end of described parasitic PAD electric capacity Cpd, and the other end is connected between described intrinsic capacity Cgd and Cds; The other end ground connection of described parasitic PAD electric capacity Cpd; Described parasitic PAD electric capacity Cpgd one end is connected to the cascaded structure of described stray inductance Lg and described dead resistance Rg formation and the link of described parasitic PAD electric capacity Cpg, and the other end is connected to the cascaded structure of described stray inductance Ld and described dead resistance Rd formation and the link of described parasitic PAD electric capacity Cpd; Described stray inductance Ls connects to form cascaded structure with described dead resistance Rs, and cascaded structure one end that described stray inductance Ls and described dead resistance Rs is formed is connected to described channel resistance Ri one end away from described intrinsic capacity Cgs, other end ground connection.

Due to device in normal operation, all there is inevitable leakage current under grid and grid both sides, therefore, the present invention is on the basis of existing AlGaN/GaNHEMT small-signal model, set up the conductance Ggsf that is suitable for characterizing and leaks electricity between grid leak and be suitable for characterizing the conductance Ggdf leaked electricity between grid source, in the diagram, the conductance Ggsf of described sign grid leak electricity and Ggdf characterizes with grid source bleeder resistance Rgsf and grid leak bleeder resistance Rgdf respectively, Ggsf=1/Rgsf, Ggdf=1/Rgdf; Add these two elements of grid source bleeder resistance Rgsf and grid leak bleeder resistance Rgdf in described AlGaN/GaNHEMT small-signal model after, device property can be reflected more accurately, improve device model accuracy rate.

Refer to Fig. 5 to Fig. 8, what the present invention also provided a kind of AlGaN/GaNHEMT small-signal model puies forward ginseng method, described in put forward ginseng method and at least comprise the following steps:

1) under low frequency, cut-off condition, measure the S parameter of peripheral open circuit, and S parameter is transformed into obtains Y parameter, obtain the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd according to Y parameter; Described parasitic PAD electric capacity Cpg, Cpd and Cpgd be the gross effect of coupling capacitance between grid end, source and the ghost effect between drain terminal metal and substrate and three electrodes mainly;

2) at low frequency, gs>Vth (threshold voltage), under the forward biased condition of Vds=0, measure the S parameter of peripheral open circuit, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, obtains the numerical value of stray inductance Lg, Ls and Ld according to Z parameter;

3) under high-frequency, cut-off condition, measure the S parameter of peripheral open circuit, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, obtains the numerical value of dead resistance Rg, Rs and Rd according to Z parameter;

4) at Vgs>Vpinch-off (shutoff voltage), under the forward biased condition of Vds=0, measure the S parameter of AlGaN/GaNHETM device, go embedding step 1) the parasitic PAD electric capacity Cpg that obtains, Cpd and Cpgd, step 2) the stray inductance Lg that obtains, Ls and Ld and step 3) the dead resistance Rg that obtains, Rs and Rd, obtain the intrinsic S parameter of inner parameter, the conversion of intrinsic S parameter is obtained Y parameter, intrinsic parameters intrinsic capacity Cgd can be tried to achieve according to Y parameter, Cgs and Cds, channel resistance Ri, mutual conductance gm, mutual conductance delay factor τ, output admittance Gds and conductance Ggsf, the numerical value of Ggdf.

Concrete, the physical significance of each parameter extracted is respectively:

Described parasitic PAD electric capacity Cpg, Cpd and Cpgd be the gross effect of coupling capacitance between grid end, source and the ghost effect between drain terminal metal and substrate and three electrodes mainly;

Described stray inductance Lg, Ld and the Ls mainly ghost effect that is made up of the metal of device surface of grid end, drain terminal and source place, described stray inductance Lg, Ld and Ls have larger impact to device performance, especially under high frequency condition;

Described dead resistance Rd and Rs characterizes drain terminal and source metal ohmic contact resistance respectively, also comprise the bulk resistor that diffusion is injected with source region simultaneously, and described dead resistance Rg mainly grid end Schottky gate metals brings; Described dead resistance Rg, Rd and Rs change along with bias voltage sometimes, but in small-signal model, it has been generally acknowledged that its resistance value is constant;

It is medium that described intrinsic capacity Cgs can regard space charge region as, in grid and source electrode and the electric capacity sum that formed between grid and raceway groove; With it similarly, the described intrinsic capacity Cgd electric capacity sum that is then grid and drain electrode and formed between grid and raceway groove; Described intrinsic capacity Cds is used for characterizing the coupling capacitance between source-drain electrode;

The change that described mutual conductance Gm is used for weighing input gate source voltage Vgs is exporting this variable on drain-source current Ids, and this physical parameter gives the internal gain of device, is important devices index when weighing microwave and Millimeter Wave Applications;

The electric charge that during described mutual conductance delay factor τ sign Vgs change, under grid, how spatial point goes redistributes the time needed for another stable state by a stable state; Described channel resistance Ri is the resistance between raceway groove and source electrode;

Described output admittance Gds is used for weighing the change exporting drain-source voltage Vds and is exporting the variable quantity on drain-source current Ids, and it characterizes the maximum voltage gain obtained from device, and very important to the best output impedance coupling of determining device;

In AlGaN/GaNHEMT device, conduction current situation between grid source and grid leak can be equivalent to exists a schottky diode between grid source and grid leak, obstruction Ggsf suffered when gate current conducts in schottky diode, Ggdf (or Rgsf, Rgdf) characterize, wherein, Ggsf=1/Rgsf, Ggdf=1/Rgdf; Obviously, when added gate voltage is greater than the cut-in voltage of diode, schottky diode conducting, the value of Rgsf and Rgdf is less, and the value of Ggsf and Ggdf is larger.

Concrete, described step 1) in obtain described step 1) in obtain the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd concrete grammar be:

Under cut-off condition, Ids and gm is all approximately 0, when low frequency, the impact of stray inductance and dead resistance all can be ignored, the equivalent electrical circuit of device architecture is simplified, under cut-off condition after simplification, small-signal low frequency equivalent electrical circuit as shown in Figure 6, the S parameter of peripheral open circuit under measuring cut-off condition, and S parameter conversion is obtained Y parameter, the imaginary part of Y parameter can be written as:

$\frac{\mathrm{Im}\left(Y_{11}\right)}{w}=C_{pg}+C_{gs}+C_{pgd}+C_{gd}$

$\frac{\mathrm{Im}\left(Y_{22}\right)}{w}=C_{pd}+C_{ds}+C_{pgd}+C_{gd}$

$-\frac{\mathrm{Im}\left(Y_{12}\right)}{w}=C_{pgd}+C_{gd}$

Intrinsic capacity proportional zoom formula can be written as:

C _gd(W)＝C _gdo·W

C _gs(W)＝C _gso·W

C _ds(W)＝C _dso·W

Herein, Cgd, Cgs, Cds are the intrinsic capacity under device cut-off state, and Cgdo, Cgso, Cdso are scale factor, and W is device grid width.

Intrinsic capacity proportional zoom formula is updated in Y parameter imaginary part expression formula and can obtains following formula:

$\frac{\mathrm{Im}\left(Y_{11}\right)}{w}=C_{pg}+C_{pgd}+W\·(C_{gdo}+C_{gso})$

$\frac{\mathrm{Im}\left(Y_{22}\right)}{w}=C_{pd}+C_{pgd}+W\·(C_{gdo}+C_{dso})$

$-\frac{\mathrm{Im}\left(Y_{12}\right)}{w}=C_{pgd}+W\·C_{gdo}$

Wherein, Cgdo, Cgso, Cdso are scale factor, and W is device grid width; According to the linear relationship of Y parameter imaginary part frequency response Im (Yij)/ω with device grid width W, the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd can be drawn respectively through the intercept of linear fit.

Concrete, described step 2) in obtain stray inductance Lg, the concrete grammar of numerical value of Ls and Ld is:

At Vgs>Vth, under the forward biased condition of Vds=0, gm=0, Cgs=Cgd=Cds=0, the equivalent electrical circuit of device architecture is simplified, under forward biased condition after simplification, equivalent electrical circuit as shown in Figure 7, measure the S parameter of peripheral open circuit, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, directly can be obtained the numerical value of stray inductance Lg, Ls and Ld by the imaginary part of Z parameter and ω:

$L_g=\frac{\mathrm{Im}(Z_{11}-Z_{12})}{w}$

$L_d=\frac{\mathrm{Im}(Z_{22}-Z_{12})}{w}$

$L_s=\frac{\mathrm{Im}\left(Z_{12}\right)}{w}$

Concrete, described step 3) in obtain dead resistance Rg, the concrete grammar of numerical value of Rs and Rd is:

Under cut-off condition, the equivalent electrical circuit of device architecture is simplified, under cut-off condition after simplification, small-signal high frequency equivalent circuit as shown in Figure 8, measure the S parameter of peripheral open circuit, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, directly can obtain the numerical value of dead resistance Rg, Rs and Rd according to the real part of Z parameter:

R _g＝Re(Z ₁₁-Z ₁₂)

R _d＝Re(Z ₂₂-Z ₁₂)

R _s＝Re(Z ₁₂)＝Re(Z ₂₁)

The method utilizing the S parameter in cut-off situation to extract dead resistance extracts dead resistance.The method does not rely on forward bias grid schottky junction, eliminate the grid degeneration that large gate current causes, and all dead resistances directly can obtain, and eliminate the uncertainty in Cold-FET method.Described Cold-FET method is utilize radio frequency S parameter under grid schottky diode forward biased condition to determine the method for dead resistance and inductance.

It should be noted that, in the present embodiment, the frequency of described low frequency is less than 5GHz, and the frequency of described high frequency is 30GHz ~ 40GHz.

Concrete, step 4) in, described step 4) in obtain intrinsic parameters intrinsic capacity Cgd, Cgs and Cds, channel resistance Ri, mutual conductance gm, mutual conductance delay factor τ, output admittance Gds and conductance Ggsf, Ggdf the concrete grammar of numerical value be:

At Vgs>Vpinch-off (shutoff voltage), under the forward biased condition of Vds=0, measure the S parameter of AlGaN/GaNHETM device, go embedding step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, step 2) the stray inductance Lg, Ls and Ld and the step 3 that obtain) the dead resistance Rg, Rs and Rd that obtain, obtain the intrinsic S parameter of inner parameter, the conversion of intrinsic S parameter obtained Y parameter:

$Y_{11}=\frac{1}{R_i+\frac{1}{G_{gsf}+{\mathrm{jwC}}_{gs}}}+\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

$Y_{12}=-\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

$Y_{21}=\frac{g_m{e}^{-jw\mathrm{\τ}}}{R_i{G}_{gsf}+{\mathrm{jwC}}_{gs}{R}_i+1}-\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

$Y_{22}=G_{ds}+\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}+{\mathrm{jwC}}_{ds}$

Above-mentioned formula is carried out simplify processes and obtains Ygs, Ygd, Ygm and Yds:

$Y_{gs}=Y_{11}+Y_{12}=\frac{1}{R_i+\frac{1}{G_{gsf}+{\mathrm{jwC}}_{gs}}}=\frac{G_{gsf}+{\mathrm{jwC}}_{gs}}{1+R_i{G}_{gsf}+{\mathrm{jwR}}_i{C}_{gs}}$

Y _gd＝-Y ₁₂＝G _gdf+jwC _gd

$Y_{gm}=Y_{21}-Y_{12}=\frac{g_m{e}^{-jw\mathrm{\τ}}}{R_i{G}_{gsf}+{\mathrm{jwC}}_{gs}+1}$

Y _ds＝Y _i,22+Y _i,12＝G _ds+jwC _ds

Definition: $A=\frac{{\left|Y_{gs}\right|}^2}{\mathrm{Im}\[Y_{gs}\]}=\frac{{G_{gsf}}^2}{{\mathrm{wC}}_{gs}}+{\mathrm{wC}}_{gs}$

$B=\frac{Y_{gs}}{\mathrm{Im}\[Y_{gs}\]}=\frac{G_{gsf}(1+R_i{G}_{gsf})}{{\mathrm{wC}}_{gs}}+{\mathrm{wR}}_i{C}_{gs}-j$

$C={\left|\frac{Y_{gs}}{Y_{gm}}\right|}^2={\left(\frac{G_{gsf}}{g_m}\right)}^2+{\left(\frac{C_{gs}}{g_m}\right)}^2{w}^2$

$D=(G_{gsf}+{\mathrm{jwC}}_{gs})\frac{Y_{gm}}{Y_{gs}}=g_m{e}^{-jw\mathrm{\τ}}$

To ω ²~ A ω curve carries out linear fit can obtain Cgs; In conjunction with the Cgs obtained, to ω B ~ ω ²curve carries out linear fit can obtain Ri; Real part according to Ygs can determine Ggsf; According to formula Y _gd=-Y ₁₂=G _gdf+ jwC _gdthe corresponding relation of middle real and imaginary part can obtain Cgd and Ggdf; In conjunction with the Cgs obtained, to ω ²~ C curve carries out linear fit can obtain gm; Linear fit is carried out to ω ~ D curve and can obtain τ; According to formula Y _ds=Y _{i, 22}+ Y _{i, 12}=G _ds+ jwC _dsthe corresponding relation of middle real and imaginary part can obtain Gds and Cds.

In sum, the invention provides a kind of AlGaN/GaNHETM small-signal model and put forward ginseng method, the present invention is on the basis of existing AlGaN/GaNHEMT small-signal model, set up the grid leak bleeder resistance Rgsf that is suitable for characterizing and leaks electricity between grid leak and be suitable for characterizing the grid source bleeder resistance Rgdf leaked electricity between grid source, due to device in normal operation, all there is inevitable leakage current under grid and grid both sides, therefore, after adding these two elements, device property can be reflected more accurately, improve device model accuracy rate.

Above-described embodiment is illustrative principle of the present invention and effect thereof only, but not for limiting the present invention, such as, the present invention also can adopt three epitaxial loayers or many epitaxial loayers.Any person skilled in the art scholar all without prejudice under spirit of the present invention and category, can modify above-described embodiment or changes.Therefore, such as have in art usually know the knowledgeable do not depart from complete under disclosed spirit and technological thought all equivalence modify or change, must be contained by claim of the present invention.

Claims (9)

1. AlGaN/GaNHETM small-signal model put forward a ginseng method, it is characterized in that, described in put forward ginseng method and comprise;

1) measure the S parameter of peripheral open circuit, and S parameter is transformed into obtains Y parameter, obtain the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd according to Y parameter;

2) S parameter of peripheral open circuit is measured, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, obtains the numerical value of stray inductance Lg, Ls and Ld according to Z parameter;

3) S parameter of peripheral open circuit is measured, removal step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, obtains the numerical value of dead resistance Rg, Rs and Rd according to Z parameter;

4) S parameter of AlGaN/GaNHETM device is measured, go embedding step 1) parasitic PAD electric capacity Cpg, Cpd and Cpgd of obtaining, step 2) the stray inductance Lg, Ls and Ld and the step 3 that obtain) the dead resistance Rg, Rs and Rd that obtain, obtain the intrinsic S parameter of inner parameter, the conversion of intrinsic S parameter is obtained Y parameter, the numerical value of intrinsic parameters intrinsic capacity Cgd, Cgs and Cds, channel resistance Ri, mutual conductance gm, mutual conductance delay factor τ, output admittance Gds and conductance Ggsf, Ggdf can be tried to achieve according to Y parameter.

2. AlGaN/GaNHETM small-signal model according to claim 1 put forward ginseng method, it is characterized in that: described step 1) under low frequency, cut-off condition, measure the S parameter of peripheral open circuit; Described step 2) under the forward biased condition of low frequency, Vgs>Vth, Vds=0, measure the S parameter of peripheral open circuit; Described step 3) under high-frequency, cut-off condition, measure the S parameter of peripheral open circuit; Described step 4) under the forward biased condition of Vgs>Vpinch-off, Vds=0, measure the S parameter of AlGaN/GaNHETM device.

3. AlGaN/GaNHETM small-signal model according to claim 1 put forward ginseng method, it is characterized in that: described step 1) in obtain the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd concrete grammar be:

S parameter conversion is obtained Y parameter, through being converted to following formula:

$\frac{\mathrm{Im}\left(Y_{11}\right)}{w}=C_{pg}+C_{pgd}+W\·(C_{gdo}+C_{gso})$

$\frac{\mathrm{Im}\left(Y_{22}\right)}{w}=C_{pd}+C_{pgd}+W\·(C_{gdo}+C_{dso})$

$-\frac{\mathrm{Im}\left(Y_{12}\right)}{w}=C_{pgd}+W\·C_{gdo}$

Wherein, Cgdo, Cgso, Cdso are scale factor, and W is device grid width; According to the linear relationship of Y parameter imaginary part frequency response Im (Yij)/ω with device grid width W, the numerical value of parasitic PAD electric capacity Cpg, Cpd and Cpgd can be drawn respectively through the intercept of linear fit.

4. AlGaN/GaNHETM small-signal model according to claim 1 put forward ginseng method, it is characterized in that: described step 2) in obtain stray inductance Lg, the concrete grammar of numerical value of Ls and Ld is: the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, and the imaginary part of Z parameter and ω being divided by directly to obtain the numerical value of stray inductance Lg, Ls and Ld.

5. AlGaN/GaNHETM small-signal model according to claim 1 put forward ginseng method, it is characterized in that: described step 3) in obtain dead resistance Rg, the concrete grammar of numerical value of Rs and Rd is: the S parameter conversion of removing parasitic PAD electric capacity Cpg, Cpd and Cpgd is obtained Z parameter, directly can obtain the numerical value of dead resistance Rg, Rs and Rd according to the real part of Z parameter.

6. AlGaN/GaNHETM small-signal model according to claim 1 put forward ginseng method, it is characterized in that: described step 4) in obtain intrinsic parameters intrinsic capacity Cgd, Cgs and Cds, channel resistance Ri, mutual conductance gm, mutual conductance delay factor τ, output admittance Gds and conductance Ggsf, Ggdf the concrete grammar of numerical value be: the conversion of intrinsic S parameter is obtained Y parameter, obtains following formula:

$Y_{11}=\frac{1}{R_i+\frac{1}{G_{gsf}+{\mathrm{jwC}}_{gs}}}+\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

$Y_{12}=-\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

$Y_{21}=\frac{g_m{e}^{-jw\mathrm{\τ}}}{R_i{G}_{gsf}+{\mathrm{jwC}}_{gs}{R}_i+1}-\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}$

$Y_{22}=G_{ds}+\frac{1}{\frac{1}{G_{gdf}+{\mathrm{jwC}}_{gd}}}+{\mathrm{jwC}}_{ds}$

Above-mentioned formula is carried out simplify processes and obtains Ygs, Ygd, Ygm and Yds:

$Y_{gs}=Y_{11}+Y_{12}=\frac{1}{R_i+\frac{1}{G_{gsf}+{\mathrm{jwC}}_{gs}}}=\frac{G_{gsf}+{\mathrm{jwC}}_{gs}}{1+R_i{G}_{gsf}+{\mathrm{jwR}}_i{C}_{gs}}$

Y _gd＝-Y ₁₂＝G _gdf+jwC _gd

$Y_{gm}=Y_{21}-Y_{12}=\frac{g_m{e}^{-jw\mathrm{\τ}}}{R_i{G}_{gsf}+{\mathrm{jwC}}_{gs}+1}$

Y _ds＝Y _i,22+Y _i,12＝G _ds+jwC _ds

Definition: $A=\frac{{\left|Y_{gs}\right|}^2}{\mathrm{Im}\[Y_{gs}\]}=\frac{{G_{gsf}}^2}{{\mathrm{wC}}_{gs}}+{\mathrm{wC}}_{gs}$

$B=\frac{Y_{gs}}{\mathrm{Im}\[Y_{gs}\]}=\frac{G_{gsf}(1+R_i{G}_{gsf})}{{\mathrm{wC}}_{gs}}+{\mathrm{wR}}_i{C}_{gs}-j$

$C={\left|\frac{Y_{gs}}{Y_{gm}}\right|}^2={\left(\frac{G_{gsf}}{g_m}\right)}^2+{\left(\frac{C_{gs}}{g_m}\right)}^2{w}^2$

$D=(G_{gsf}+{\mathrm{jwC}}_{gs})\frac{Y_{gm}}{Y_{gs}}=g_m{e}^{-jw\mathrm{\τ}}$

To ω ²~ A ω curve carries out linear fit can obtain Cgs; In conjunction with the Cgs obtained, to ω B ~ ω ²curve carries out linear fit can obtain Ri; Real part according to Ygs can determine Ggsf; According to formula Y _gd=-Y ₁₂=G _gdf+ jwC _gdmiddle plural corresponding relation can obtain Cgd and Ggdf; In conjunction with the Cgs obtained, to ω ²~ C curve carries out linear fit can obtain gm; Linear fit is carried out to ω ~ D curve and can obtain τ; According to formula Y _ds=Y _{i, 22}+ Y _{i, 12}=G _ds+ jwC _dsthe corresponding relation of middle real and imaginary part can obtain Gds and Cds.

7. an AlGaN/GaNHETM small-signal model, is characterized in that, described AlGaN/GaNHETM small-signal model comprises spurious portion and intrinsic part; Described intrinsic part comprises the grid leak bleeder resistance Rgdf that is suitable for characterizing and leaks electricity between grid leak and is suitable for characterizing the grid source bleeder resistance Rgsf leaked electricity between grid source.

8. AlGaN/GaNHETM small-signal model according to claim 7, is characterized in that:

Described intrinsic part comprises intrinsic capacity Cgd, Cgs and Cds, grid source bleeder resistance Rgsf, grid leak bleeder resistance Rgdf, channel resistance Ri, source and drain resistance Rds and mutual conductance Gm; Wherein,

Described intrinsic capacity Cgs connects to form cascaded structure with after the bleeder resistance Rgsf parallel connection of described grid source with described channel resistance Ri;

Described intrinsic capacity Cds connects to form cascaded structure with after described source and drain resistance Rds and described mutual conductance Gm parallel connection with described intrinsic capacity Cgd, and described grid leak bleeder resistance Rgdf is in parallel with described intrinsic capacity Cgd;

The cascaded structure that described intrinsic capacity Cds, described source and drain resistance Rds, described mutual conductance Gm and described intrinsic capacity Cgd are formed and the tandem construction parallel that described intrinsic capacity Cgs, described grid source bleeder resistance Rgsf and described channel resistance Ri are formed.

9. AlGaN/GaNHETM small-signal model according to claim 8, is characterized in that:

Described spurious portion comprises parasitic PAD electric capacity Cpg, Cpd and Cpgd, stray inductance Lg, Ld and Ls, dead resistance Rg, Rd and Rs; Wherein,

Described stray inductance Lg connects to form cascaded structure with described dead resistance Rg, cascaded structure one end that described stray inductance Lg and described dead resistance Rg is formed is connected to one end of described parasitic PAD electric capacity Cpg, and the other end is connected between described intrinsic capacity Cgd and Cgs; The other end ground connection of described parasitic PAD electric capacity Cpg;

Described stray inductance Ld connects to form cascaded structure with described dead resistance Rd, cascaded structure one end that described stray inductance Ld and described dead resistance Rd is formed is connected to one end of described parasitic PAD electric capacity Cpd, and the other end is connected between described intrinsic capacity Cgd and Cds; The other end ground connection of described parasitic PAD electric capacity Cpd;

Described parasitic PAD electric capacity Cpgd one end is connected to the cascaded structure of described stray inductance Lg and described dead resistance Rg formation and the link of described parasitic PAD electric capacity Cpg, and the other end is connected to the cascaded structure of described stray inductance Ld and described dead resistance Rd formation and the link of described parasitic PAD electric capacity Cpd;

Described stray inductance Ls connects to form cascaded structure with described dead resistance Rs, and cascaded structure one end that described stray inductance Ls and described dead resistance Rs is formed is connected to described channel resistance Ri one end away from described intrinsic capacity Cgs, other end ground connection.