A method and device for extracting HBT device process parameters based on ADS

Abstract

The embodiment of the present invention discloses a method and apparatus for extracting HBT device process parameters based on ADS. The method includes: establishing a first HBT simulation circuit model; the HBT simulation circuit model includes an HBT circuit, a negative resistor r b and port, the negative resistance r b The two ends of the port are connected to the HBT circuit respectively, and one end of the port is grounded; according to the process parameter extraction requirements, multiple sets of simulation parameters are set; the multiple sets of simulation parameters are multiple different base resistances r b resistance; simulate according to the first HBT simulation circuit model and simulation parameters to obtain a first simulation curve; determine the base resistance r according to the first simulation curve b The embodiment of the present invention solves the problem that designers cannot know the above important parameters by establishing an HBT simulation circuit model and combining simulation technology to extract important process parameters in the HBT device.

Description

Technical Field

[0001] The present invention relates to the field of chip technology, and in particular to a method and device for extracting HBT device process parameters based on ADS. Background Art

[0002] ADS is a commonly used compound semiconductor chip design software. Design generally requires the use of the design package (PDK) provided by the foundry, which contains its device model and process parameters implicitly contained in the model. For circuit design, the more important process parameters are BE capacitor C π , BC capacitor C μ , BE small signal resistor r π , base resistance r b , transconductance g m .

[0003] However, foundries generally do not explicitly provide the above parameters, which brings difficulties to designers. For example, designers need to roughly know the process cutoff frequency f T When , it is simply calculated by the following formula:

[0004] f T =g m / (2πC π )

[0005] Since it is impossible to know g m and C π , f T It cannot be calculated. Summary of the Invention

[0006] In view of the technical deficiencies mentioned in the background art, an object of the embodiments of the present invention is to provide a method and apparatus for extracting process parameters of an HBT device based on ADS.

[0007] To achieve the above objectives, in a first aspect, an embodiment of the present invention provides a method for extracting HBT device process parameters based on ADS, comprising:

[0008] Establish a first HBT simulation circuit model; the HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and port, the negative resistance -r b Two ends of the port are connected to the HBT circuit respectively, and one end of the port is grounded;

[0009] According to the process parameter extraction requirements, multiple groups of simulation parameters are set; the multiple groups of simulation parameters are multiple different base resistances r b resistance value;

[0010] Perform simulation according to the first HBT simulation circuit model and simulation parameters to obtain a first simulation curve graph;

[0011] Determine the base resistance r according to the first simulation curve b The target resistance value.

[0012] Furthermore, the base resistance r is determined according to the first simulation curve. b After the target resistance value is obtained, the method further includes:

[0013] The negative resistance -r in the first HBT simulation circuit model b The resistance value of the base resistance r b Target resistance value;

[0014] Perform simulation according to the first HBT simulation circuit model to obtain a second simulation curve graph;

[0015] Determine the BE small resistor r according to the second simulation curve π The target resistance value.

[0016] Furthermore, as a preferred embodiment of the present application, the method further includes:

[0017] Establish a second HBT simulation circuit model; the second HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b Two ends of the port are connected to the voltage source and the HBT circuit respectively, and one end of the port is grounded;

[0018] Perform AC simulation based on the second HBT simulation circuit model to obtain the current I of the HBT device. test ;

[0019] According to the formula g m =I test / V test Solving for the transconductance g m ; Among them, V test The voltage provided by the voltage source.

[0020] Furthermore, the base resistance r is determined according to the first simulation curve. b After the target resistance value is obtained, the method further includes:

[0021] According to the first simulation curve, the BE capacitance C π , BC capacitor C μ sum;

[0022] Establish a third HBT simulation circuit model; the third HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r bOne end of the voltage source is grounded, and the other end is connected to the left side of the HBT circuit; one end of the voltage source is grounded, and the other end is connected to the right side of the HBT circuit;

[0023] Simulation is performed based on the third HBT simulation circuit model to obtain the BC capacitance C μ ;

[0024] According to the BE capacitor C π , BC capacitor C μ The sum of the BC capacitor C μ Calculate the BE capacitance C π .

[0025] As a specific embodiment of the present application, the HBT circuit includes a base resistor r b BE capacitor C π , BC capacitor C μ , BE small signal resistor r π and transconductance g m , the base resistance r b One end of the BE capacitor C π , BC capacitor C μ and BE small signal resistance r π One end of the BE capacitor C π and BE small signal resistor r π The other end of the BC capacitor C μ The other end of the transconductor g m One end, transconductance g m The other end is grounded.

[0026] In a second aspect, an embodiment of the present invention further provides a device for extracting HBT device process parameters based on ADS, comprising:

[0027] A model building module is used to build a first HBT simulation circuit model; the HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and port, the negative resistance -r b Two ends of the port are connected to the HBT circuit respectively, and one end of the port is grounded;

[0028] Simulation modules for:

[0029] According to the process parameter extraction requirements, multiple groups of simulation parameters are set; the multiple groups of simulation parameters are multiple different base resistances r b resistance value;

[0030] Perform simulation according to the first HBT simulation circuit model and simulation parameters to obtain a first simulation curve graph;

[0031] Determine the base resistance r according to the first simulation curve b The target resistance value.

[0032] As a preferred embodiment, the simulation module is further used for:

[0033] The negative resistance -r in the first HBT simulation circuit model b The resistance value of the base resistance r b Target resistance value;

[0034] Perform simulation according to the first HBT simulation circuit model to obtain a second simulation curve graph;

[0035] Determine the BE small resistor r according to the second simulation curve π The target resistance value.

[0036] As a preferred embodiment, the simulation module is further used for:

[0037] Establish a second HBT simulation circuit model; the second HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b Two ends of the port are connected to the voltage source and the HBT circuit respectively, and one end of the port is grounded;

[0038] Perform AC simulation based on the second HBT simulation circuit model to obtain the current I of the HBT device. test ;

[0039] According to the formula g m =I test / V test Solving for the transconductance g m ; Among them, V test The voltage provided by the voltage source.

[0040] As a preferred embodiment, the simulation module is further used for:

[0041] According to the first simulation curve, the BE capacitance C π , BC capacitor C μ sum;

[0042] Establish a third HBT simulation circuit model; the third HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b One end of the voltage source is grounded, and the other end is connected to the left side of the HBT circuit; one end of the voltage source is grounded, and the other end is connected to the right side of the HBT circuit;

[0043] Simulation is performed based on the third HBT simulation circuit model to obtain the BC capacitance C μ ;

[0044] According to the BE capacitor C π , BC capacitor C μ The sum of the BC capacitor C μ Calculate the BE capacitance C π .

[0045] The embodiment of the present invention solves the problem that designers cannot know the important parameters by establishing an HBT simulation circuit model and combining simulation technology to extract important process parameters in the HBT device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the specific implementation or the description of the prior art.

[0047] Figure 1 It is a small signal equivalent circuit diagram commonly used in HBT;

[0048] Figure 2a is a schematic diagram of a first HBT simulation circuit model in an embodiment of the present invention;

[0049] Figure 2b is the first simulation curve graph;

[0050] Figure 3 is the second simulation curve graph;

[0051] Figure 4a is a schematic diagram of a second HBT simulation circuit model in an embodiment of the present invention;

[0052] Figure 4b is to solve for the transconductance g m Simulation curve diagram of

[0053] Figure 5a is a schematic diagram of a third HBT simulation circuit model in an embodiment of the present invention;

[0054] Figure 5b Is to solve BC capacitance C μ Simulation curve diagram of

[0055] Figure 6 is the final small-signal equivalent circuit. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0057] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0058] For HBT circuit design, the more important process parameters are BE capacitance C π , BC capacitor C μ , BE small signal resistor r π , base resistance r b , transconductance g m These important process parameters can be composed of Figure 1 The small signal equivalent circuit shown. The embodiments of the present invention are based on this small signal equivalent circuit. It should be noted that in the subsequent embodiments, this application describes the small signal equivalent circuit as an HBT circuit, and the HBT circuit does not include a peripheral circuit to maintain a normal DC operating point.

[0059] like Figure 1 As shown, the HBT circuit includes a base resistor r b BE capacitor C π , BC capacitor C μ , BE small signal resistor r π and transconductance g m , the base resistance r b One end of the BE capacitor C π , BC capacitor C μ and BE small signal resistance r π One end of the BE capacitor C π and BE small signal resistor r π The other end of the BC capacitor C μ The other end of the transconductor g m One end, transconductance g m The other end is grounded.

[0060] The method for extracting HBT device process parameters based on ADS provided in an embodiment of the present invention mainly includes:

[0061] 1. Calculate the base resistance r b

[0062] (1) Establish the first HBT simulation circuit model.

[0063] Among them, Figure 2a As shown, the first HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and port, the negative resistance -r b Two ends of the MOSFET are respectively connected to the port and the HBT circuit, and one end of the port is grounded.

[0064] (2) According to the process parameter extraction requirements, multiple groups of simulation parameters are set.

[0065] Among them, the multiple groups of simulation parameters are multiple different base resistances r b resistance value.

[0066] (3) Perform simulation according to the first HBT simulation circuit model and simulation parameters to obtain a first simulation curve graph.

[0067] (4) Determine the base resistance r according to the first simulation curve b Target resistance value 2. Calculate the BE small resistor r π .

[0068] Specifically, please refer to Figure 2a , connect the HBT device according to the diagram, note that an external device is connected as a negative resistor, and the resistance value is set as the variable -r b , perform S-Parameter simulation and scan multiple groups of different r b value.

[0069] After the simulation is completed, the formula C_pi_mu=imag(Y11) / 2 / pi / SP.freq can be used to obtain Figure 2b The results shown.

[0070] Theoretically, at the same DC bias point, the capacitance should not change with frequency, so Figure 2b The frequency variation of some curves is due to the fact that the imaginary part of the Y parameter is affected by r b The effect of resistance; the flatter curve is due to negative resistance -r b Offsets the r inside the HBT tube b The resistor will show the pure imaginary part. Therefore, the value obtained by selecting the flattest curve is C π with C μ The sum of Figure 2b The curve marked by m1, at this time r b is 8Ω, C π with C μ The sum is 2.423pF.

[0071] 2. Calculate the resistance r of the BE small π

[0072] (1) The negative resistance -r in the first HBT simulation circuit model is b The resistance value of the base resistance r b The target resistance value.

[0073] (2) Perform simulation according to the first HBT simulation circuit model to obtain a second simulation curve graph.

[0074] (3) Determine the BE small resistor r according to the second simulation curve π The target resistance value.

[0075] Specifically, the calculated base resistance r is not changed b The circuit solution is to simply replace Figure 2a The external negative resistance is set to 8Ω. After the simulation is completed, the formula r_pi=real(Z11) can be used to obtain Figure 3 The results shown.

[0076] Since the real part of Z is disturbed by the capacitor at high frequencies, the real part of Z at low frequencies is r π ,Right now Figure 3 The value of the m2 mark is 197.95 ohms.

[0077] 3. Calculating transconductance g m

[0078] (1) Establish the second HBT simulation circuit model.

[0079] The second HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b The two ends of the port are respectively connected to the voltage source and the HBT circuit, and one end of the port is grounded.

[0080] (2) Perform AC simulation based on the second HBT simulation circuit model to obtain the current I of the HBT device test .

[0081] (3) According to formula g m =I test / V test Solving for the transconductance g m ; Among them, V test The voltage provided by the voltage source.

[0082] Specifically, the HBT is pressed Figure 4a Connect, the original Figure 2a Replace Port1 in the example with a voltage source and perform AC simulation. The AC voltage is Vtest , keeping other structures unchanged, observe the Collector AC current I test The obtained simulation diagram is as follows: Figure 4b shown.

[0083] Figure 4a In the equation, since the negative resistance and positive resistance cancel each other out, -r b The left end and r b The voltage on the right side is V test , so I test V test That is the transconductance g m , that is, g m =I test / V test .like Figure 4b The transconductance is marked by m3 in the figure, and is about 0.359S.

[0084] 4. Calculate BC capacitance C μ and BE capacitor C Π

[0085] (1) Establish the third HBT simulation circuit model.

[0086] The third HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b One end of the voltage source is grounded, and the other end is connected to the left side of the HBT circuit; one end of the voltage source is grounded, and the other end is connected to the right side of the HBT circuit.

[0087] (2) Based on the third HBT simulation circuit model, simulation is performed to obtain the BC capacitance C μ .

[0088] (3) According to BE capacitance C π , BC capacitor C μ The sum of the BC capacitor C μ Calculate the BE capacitance C π .

[0089] Specifically, the HBT device is Figure 5a After connecting, perform simulation.

[0090] Also, since the negative resistance and positive resistance cancel each other out, the theoretical resistance r b The right side swing is zero, g m The current generated is zero, and V test All the generated current flows away from the Base terminal, so the following formula can be used to calculate C μ .

[0091] Cmu=Itest / Vtest / (2*pi*freq)

[0092] In fact, due to non-ideal factors, C μ May change. However, the above formula can not only observe the amplitude, but also the phase. Obviously, when the phase is 90°, C μ The value of is the most accurate. Figure 5b shown.

[0093] according to Figure 5b It can be seen that C μ It is about 60.23fF, combined with the BE capacitance C obtained in step 1 π , BC capacitor C μ The sum of C π =2.423-0.06023=2.363pF.

[0094] In summary, all common process parameters required for the design have been obtained, and the final small signal equivalent circuit is as follows Figure 6 shown.

[0095] From the above description, it can be seen that the embodiment of the present invention solves the problem that designers cannot know the above important parameters by establishing an HBT simulation circuit model and combining simulation technology to extract important process parameters in the HBT device.

[0096] Based on the same inventive concept, an embodiment of the present invention further provides a device for extracting HBT device process parameters based on ADS, comprising:

[0097] A model building module is used to build a first HBT simulation circuit model; the HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and port, the negative resistance -r b Two ends of the port are connected to the HBT circuit respectively, and one end of the port is grounded;

[0098] Simulation modules for:

[0099] According to the process parameter extraction requirements, multiple groups of simulation parameters are set; the multiple groups of simulation parameters are multiple different base resistances r b resistance value;

[0100] Perform simulation according to the first HBT simulation circuit model and simulation parameters to obtain a first simulation curve graph;

[0101] Determine the base resistance r according to the first simulation curve b The target resistance value.

[0102] Furthermore, as a preferred embodiment, the simulation module is further configured to:

[0103] The negative resistance -r in the first HBT simulation circuit model b The resistance value of the base resistance r b Target resistance value;

[0104] Perform simulation according to the first HBT simulation circuit model to obtain a second simulation curve graph;

[0105] Determine the BE small resistor r according to the second simulation curve π The target resistance value.

[0106] Furthermore, as a preferred embodiment, the simulation module is further configured to:

[0107] Establish a second HBT simulation circuit model; the second HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b Two ends of the port are connected to the voltage source and the HBT circuit respectively, and one end of the port is grounded;

[0108] Perform AC simulation based on the second HBT simulation circuit model to obtain the current I of the HBT device. test ;

[0109] According to the formula g m =I test / V test Solving for the transconductance g m ; Among them, V test The voltage provided by the voltage source.

[0110] Furthermore, as a preferred embodiment, the simulation module is further configured to:

[0111] According to the first simulation curve, the BE capacitance C π , BC capacitor C μ sum;

[0112] Establish a third HBT simulation circuit model; the third HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b One end of the voltage source is grounded, and the other end is connected to the left side of the HBT circuit; one end of the voltage source is grounded, and the other end is connected to the right side of the HBT circuit;

[0113] Simulation is performed based on the third HBT simulation circuit model to obtain the BC capacitance C μ ;

[0114] According to the BE capacitor C π , BC capacitor Cμ The sum of the BC capacitor C μ Calculate the BE capacitance C π .

[0115] It should be noted that, for more specific working procedures of the device, please refer to the aforementioned method embodiment section, which will not be repeated here.

[0116] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for extracting HBT device process parameters based on ADS, characterized in that: include: Establishing the first HBT simulation circuit model; The HBT simulation circuit model includes an HBT circuit, a negative resistor-r b and port, the negative resistance -r b Two ends of the port are connected to the HBT circuit respectively, and one end of the port is grounded; According to the process parameter extraction requirements, multiple groups of simulation parameters are set; the multiple groups of simulation parameters are multiple different base resistances r b resistance value; Perform simulation according to the first HBT simulation circuit model and simulation parameters to obtain a first simulation curve graph; Determine the base resistance r according to the first simulation curve b The target resistance value.

2. The method according to claim 1, wherein Determine the base resistance r according to the first simulation curve b After the target resistance value is obtained, the method further includes: According to the first simulation curve, the BE capacitance C π , BC capacitor C μ sum.

3. The method according to claim 1, wherein Determine the base resistance r according to the first simulation curve b After the target resistance value is obtained, the method further includes: The negative resistance -r in the first HBT simulation circuit model b The resistance value of the base resistance r b Target resistance value; Perform simulation according to the first HBT simulation circuit model to obtain a second simulation curve graph; Determine the BE small resistor r according to the second simulation curve π The target resistance value.

4. The method according to claim 1, wherein The method further comprises: Establish a second HBT simulation circuit model; the second HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b Two ends of the port are connected to the voltage source and the HBT circuit respectively, and one end of the port is grounded; Perform AC simulation based on the second HBT simulation circuit model to obtain the current I of the HBT device. test ; According to the formula g m =I test / V test Solving for the transconductance g m ; Among them, V test The voltage provided by the voltage source.

5. The method according to claim 2, wherein The method further comprises: Establish a third HBT simulation circuit model; the third HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b One end of the voltage source is grounded, and the other end is connected to the left side of the HBT circuit; one end of the voltage source is grounded, and the other end is connected to the right side of the HBT circuit; Simulation is performed based on the third HBT simulation circuit model to obtain the BC capacitance C μ ; According to the BE capacitor C π , BC capacitor C μ The sum of the BC capacitor C μ Calculate the BE capacitance C π .

6. The method according to any one of claims 1 to 5, wherein: The HBT circuit includes a base resistor r b BE capacitor C π , BC capacitor C μ , BE small signal resistor r π and transconductance g m , the base resistance r b One end of the BE capacitor C π , BC capacitor C μ and BE small signal resistance r π One end of the BE capacitor C π and BE small signal resistor r π The other end of the BC capacitor C μ The other end of the transconductor g m One end, transconductance g m The other end is grounded.

7. A device for extracting HBT device process parameters based on ADS, characterized in that: include: A model building module, used for building a first HBT simulation circuit model; The HBT simulation circuit model includes an HBT circuit, a negative resistor-r b and port, the negative resistance -r b Two ends of the port are connected to the HBT circuit respectively, and one end of the port is grounded; Simulation modules for: According to the process parameter extraction requirements, multiple groups of simulation parameters are set; the multiple groups of simulation parameters are multiple different base resistances r b resistance value; Perform simulation according to the first HBT simulation circuit model and simulation parameters to obtain a first simulation curve graph; Determine the base resistance r according to the first simulation curve b The target resistance value.

8. The device according to claim 7, wherein The simulation module is also used for: The negative resistance -r in the first HBT simulation circuit model b The resistance value of the base resistance r b Target resistance value; Perform simulation according to the first HBT simulation circuit model to obtain a second simulation curve graph; Determine the BE small resistor r according to the second simulation curve π The target resistance value.

9. The device according to claim 7, wherein The simulation module is also used for: Establish a second HBT simulation circuit model; the second HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b Two ends of the port are connected to the voltage source and the HBT circuit respectively, and one end of the port is grounded; Perform AC simulation based on the second HBT simulation circuit model to obtain the current I of the HBT device. test ; According to the formula g m =I test / V test Solving for the transconductance g m ; Among them, V test The voltage provided by the voltage source.

10. The device according to claim 7, wherein The simulation module is also used for: According to the first simulation curve, the BE capacitance C π , BC capacitor C μ sum; Establish a third HBT simulation circuit model; the third HBT simulation circuit model includes an HBT circuit, a negative resistor -r b and voltage source, the negative resistance -r b One end is grounded, and the other end is connected to the left side of the HBT circuit; One end of the voltage source is grounded, and the other end is connected to the right side of the HBT circuit; Simulation is performed based on the third HBT simulation circuit model to obtain the BC capacitance C μ ; According to the BE capacitor C π , BC capacitor C μ The sum of the BC capacitor C μ Calculate the BE capacitance C π .

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