CN104635135A - De-embedding method of compound semiconductor device - Google Patents

Abstract

The invention discloses a method for de-embedding a compound semiconductor device, belonging to the technical field of microelectronic integrated circuits. The method includes: analyzing the on-chip test structure of the compound semiconductor device to determine the parasitic effect generated by the compound semiconductor device; and removing the parasitic effect step by step from the outside to the inside according to the generated parasitic effect. The invention provides a reasonable analysis of the layout structure of the on-chip test, has practical physical significance, completely characterizes and removes possible parasitic effects; improves the shortcomings of the traditional de-embedding method, improves the de-embedding bandwidth, and ensures higher frequency range of de-embedding accuracy and validity for high-frequency device models and circuit applications. In addition, the invention fully considers and characterizes all possible parasitic effects from the physical source, improves the precision and bandwidth of de-embedding, and has practical application value.

Description

A method for de-embedding a compound semiconductor device

technical field

The invention relates to testing and modeling of semiconductor devices, in particular to a method for de-embedding a compound semiconductor device in the technical field of radio frequency devices, and belongs to the technical field of microelectronic integrated circuits.

Background technique

With the continuous shrinking of the physical feature size of semiconductor devices, the radio frequency operating range of the device gradually increases, even in the terahertz field, the increase of frequency means the decrease of wavelength. This conclusion is used in radio frequency circuits, that is, when the wavelength can be compared with discrete circuits When the geometric dimensions of the components are compared, the voltage and current no longer keep the space constant, and they must be regarded as transmitted waves. Therefore, the influence of parasitic parameters on the high-frequency performance of the device is becoming more and more obvious, and de-embedding is to remove the semiconductor The influence of parasitic parameters in the device on the high-frequency performance of semiconductor devices, and the accurate de-embedding method is very important for obtaining the intrinsic performance parameters of semiconductor devices.

The transition to the treatment of metal wires or discrete components as transmission lines occurred gradually as wavelengths became more and more comparable to the average size of circuit components. As a rule of thumb, transmission line theory should be applied when the average size of the discrete circuit elements is greater than 1/10 the wavelength. For the transmission substrate of compound semiconductor devices, the wavelength in the transmission line can be expressed by the effective dielectric constant as:

$\mathrm{<span\; class="notranslate">\; \&lambda;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; c</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\sqrt{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; eff</span>}}}}$

For the gallium arsenide substrate material, its dielectric constant value is 12.9, and the wavelength of the transmission line in this process is about 0.8 mm at 100 GHz, so that the wavelength of 1/10 is 80 μm. When the on-chip metal connection line exceeds 80 μm At this frequency, there will be obvious errors in using lumped LC components to characterize the performance of metal connecting lines. In fact, for the needs of test probes, the size of metal pads is usually 100μm×100μm, and the size of metal pads has exceeded 1/10 of the wavelength, plus the metal interconnection from the metal pad to the input and output ports of the device, the traditional LC lumped element parasitic network obviously cannot accurately achieve the de-embedding effect, so the traditional open-short method can only be applied to frequency In the lower range, when the operating frequency of the compound semiconductor RF device is high, the traditional method of de-embedding is no longer applicable.

In addition, the increase of the frequency also indicates that the mutual interference between metal structures in the on-chip test is also a parasitic parameter that cannot be ignored, which also shows that the method of only using the transmission line cannot fully meet the requirements of de-embedding. In radio frequency circuits, it is necessary to thin the substrate to improve the performance of the circuit. The back hole can achieve good grounding, and the equivalent inductance introduced by the back hole cannot be ignored.

Contents of the invention

(1) Technical problems to be solved

With the increase of the working frequency of the compound semiconductor radio frequency device, the testing and modeling of the device are faced with a series of challenges. In view of this, the present invention provides a de-embedding method for the compound semiconductor radio frequency device.

(2) Technical solution

In order to achieve the above object, the present invention provides a method for de-embedding a compound semiconductor device, including: analyzing the on-chip test structure of the compound semiconductor device to determine the parasitic effect produced by the compound semiconductor device; and according to the generated parasitic effect, from outside to The parasitic effects are removed step by step.

In the above scheme, the analysis of the on-chip test structure of the compound semiconductor device to determine the parasitic effects produced by the compound semiconductor device specifically includes: analyzing the on-chip test structure of the compound semiconductor device to determine that the parasitic effects produced by the compound semiconductor device are from outside to inside The order is: metal pad parasitic effect, metal interconnect conversion structure parasitic effect, transmission line parasitic effect and back hole parasitic effect.

In the above solution, the parasitic effects are removed step by step from the outside to the inside according to the generated parasitic effects, specifically including: through the cascading relationship of the matrix, the parasitic effects of the metal pad and the parasitic effects of the metal interconnection conversion structure are sequentially removed from the outside to the inside , transmission line parasitic effect and back hole parasitic effect, de-embed the reference plane to the input and output ports of the intrinsic device, so as to obtain the intrinsic parameters of the compound semiconductor radio frequency device.

In the above solution, the compound semiconductor device is a compound semiconductor field effect transistor with radio frequency characteristics.

In the above solution, the metal pad parasitic effect is the parasitic effect generated by the metal pad used to realize the probe contact, including the parasitic effect generated by the forward transmission line and the backward open transmission line of the two metal pads, and the metal pad Parasitic effects generated by crosstalk capacitance between pads.

In the above solution, the parasitic effect of the metal interconnection conversion structure is the parasitic effect generated by the metal interconnection conversion structure used for the gentle transition from the metal pad to the transmission line. The metal interconnection conversion structure is composed of a lumped LC equivalent structure, and the metal interconnection The crosstalk capacitance between transition structures is merged into the other two crosstalk capacitances.

In the above solution, the parasitic effect of the transmission line is the parasitic effect produced by the transmission line used to connect the output of the intrinsic device, including the parasitic effect produced by the transmission lines on both sides and the crosstalk capacitance between them.

In the above solution, the parasitic effect of the back hole is a parasitic effect generated by the back hole for realizing common source grounding.

(3) Beneficial effects

Compared with the prior art, the above-mentioned technical solution has the following advantages:

The de-embedding method of the compound semiconductor device provided by the present invention reasonably analyzes the layout structure of the on-chip test, has practical physical significance, completely characterizes and removes possible parasitic effects; improves the shortcomings of the traditional de-embedding method, The de-embedding bandwidth is improved to ensure the accuracy of de-embedding in a higher frequency range and the validity of high-frequency device models and circuit applications. In addition, the compound semiconductor radio frequency device de-embedding method provided by the present invention fully considers and characterizes all possible parasitic effects from the physical source, improves the precision and bandwidth of de-embedding, and has practical application value.

Description of drawings

FIG. 1 is a flow chart of a de-embedding method for a compound semiconductor device provided by the present invention.

2 is a schematic diagram of de-embedding and segmentation of a compound semiconductor radio frequency device according to an embodiment of the present invention;

FIG. 3 is an equivalent circuit of parasitic parameters of a compound semiconductor radio frequency device according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The invention discloses a method for de-embedding a compound semiconductor radio frequency device. By reasonably analyzing the layout structure of the on-chip test, the parasitic effect is divided into four components, which are the parasitic parameters of the metal pad, the parasitic parameters of the metal interconnection conversion structure, and the transmission line. Parasitic parameters, back hole parasitic parameters. Through the cascade relationship of the matrix, the parasitic effects of metal pads, metal interconnection conversion structures, transmission lines and back holes are removed in turn, and the reference plane is de-embedded into the input and output ports of the intrinsic device, thereby obtaining the intrinsic parameters of the compound semiconductor radio frequency device.

As shown in Figure 1, Figure 1 is a flow chart of a de-embedding method for a compound semiconductor device provided by the present invention, the method comprising the following steps:

Step 1: Analyze the on-wafer test structure of the compound semiconductor device to determine the parasitic effects produced by the compound semiconductor device;

Step 2: Remove the parasitic effects step by step from the outside to the inside according to the generated parasitic effects.

Wherein, analyzing the on-wafer test structure of the compound semiconductor device as described in step 1, and determining the parasitic effects produced by the compound semiconductor device specifically include: analyzing the on-wafer test structure of the compound semiconductor device, and determining that the parasitic effects produced by the compound semiconductor device are from outside to The inner order is: metal pad parasitic effect, metal interconnection conversion structure parasitic effect, transmission line parasitic effect and back hole parasitic effect.

According to the generated parasitic effects described in step 2, the parasitic effects are removed step by step from the outside to the inside, specifically including: through the cascading relationship of the matrix, the metal pad parasitic effects, the metal interconnection conversion structure parasitic effects, The transmission line parasitic effect and the back hole parasitic effect de-embed the reference plane to the input and output ports of the intrinsic device, so as to obtain the intrinsic parameters of the compound semiconductor radio frequency device.

The metal pad parasitic effect is the parasitic effect generated by the metal pad used to realize the probe contact, including the parasitic effect generated by the forward transmission line and the backward open transmission line of the two metal pads, and the crosstalk between the metal pads The parasitic effect of capacitance. The parasitic effect of the metal interconnection conversion structure is the parasitic effect generated by the metal interconnection conversion structure used for the gentle transition from the metal pad to the transmission line. The metal interconnection conversion structure is composed of a lumped LC equivalent structure, and the crosstalk between the metal interconnection conversion structures Capacitors are merged into the other two crosstalk capacitors. The parasitic effect of the transmission line is the parasitic effect produced by the transmission line used to connect the output of the intrinsic device, including the parasitic effect produced by the transmission line on both sides and the crosstalk capacitance between the two. The parasitic effect of the back hole is the parasitic effect generated by the back hole used to realize the common source grounding.

In a preferred embodiment of the present invention, the compound semiconductor device is generally a compound semiconductor field effect transistor with radio frequency characteristics.

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

FIG. 2 is a schematic diagram of de-embedding and segmentation of a compound semiconductor radio frequency device according to an embodiment of the present invention. The reference plane for the actual test is REF1, which needs to be de-embedded into the input and output port REF2 of the intrinsic device to obtain the intrinsic device part 14. The parasitic effect is divided into the following components, the left metal pad 110 for probe contact and The right metal pad 111, the left metal interconnection conversion structure 120 and the right metal interconnection conversion structure 121, the left transmission line 130 used to connect the input of the intrinsic device and the right transmission line 131 used to connect the output of the intrinsic device, and realize common source grounding The upper and lower back holes 150 and 151.

FIG. 3 is an equivalent circuit of parasitic parameters of a compound semiconductor radio frequency device according to an embodiment of the present invention. The parasitic effect is composed of the following components: the forward transmission line T _p of the metal pad and the reverse open transmission line T _op , the LC lumped equivalent structures L _n1 and C _n1 of the metal interconnection structure on the left, the LC lumping of the metal interconnection structure on the right, etc. The effective structures L _n2 and C _n2 are used to connect the left transmission line T ₁ of the intrinsic device output, and the right transmission line T ₂ used to connect the intrinsic device output, realize the equivalent back hole inductance L _b of the common source grounding, and two A crosstalk capacitance C _ct1 and C _ct2 .

The S-parameters obtained by the actual test are formed by several groups of parasitic parameters and intrinsic devices according to the relationship of ABCD matrix cascading. The specific expression is as follows:

Use the impedance Z matrix to deal with the series relationship of the two-port network, and use the admittance Y matrix to deal with the parallel relationship between the two-port network. The order of removing parasitic parameters step by step from the outside to the inside is as follows: remove metal pad parasitics, remove metal interconnection conversion parasitics , Remove transmission line parasitics, remove back hole parasitics. Finally, the S-parameter results of the intrinsic device are obtained as follows:

$<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; S</span>}}^{\mathrm{<span\; class="notranslate">\; DUT</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{\mathrm{<span\; class="notranslate">\; Hole</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; left</span>}}^{\mathrm{<span\; class="notranslate">\; TLine</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; left</span>}}^{\mathrm{<span\; class="notranslate">\; TF</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{\mathrm{<span\; class="notranslate">\; PAD</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; S</span>}}^{\mathrm{<span\; class="notranslate">\; Meas</span>}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{\mathrm{<span\; class="notranslate">\; PAD</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; right</span>}}^{\mathrm{<span\; class="notranslate">\; TF</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}_{\mathrm{<span\; class="notranslate">\; right</span>}}^{\mathrm{<span\; class="notranslate">\; TLine</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{<span\; class="notranslate">\; [</span>{\mathrm{<span\; class="notranslate">\; A</span>}}^{\mathrm{<span\; class="notranslate">\; Hole</span>}}<span\; class="notranslate">\; ]</span>}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}$

The invention completely characterizes and removes the parasitic effect by reasonably dividing the parasitic composition of the layout, can improve the bandwidth and accuracy of de-embedding, and ensures the correctness of the S parameters of the intrinsic device.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. a De-embedding method for compound semiconductor device, is characterized in that, comprising:

The test structure of analysis of compounds semiconductor devices, the ghost effect that deterministic compound semiconductor devices produces; And

According to the ghost effect produced, remove ghost effect step by step from outside to inside.

2. the De-embedding method of compound semiconductor device according to claim 1, is characterized in that, the test structure of described analysis of compounds semiconductor devices, the ghost effect that deterministic compound semiconductor devices produces, and specifically comprises:

The test structure of analysis of compounds semiconductor devices, the ghost effect that deterministic compound semiconductor devices produces is followed successively by from outside to inside: metal pad ghost effect, the ghost effect of metal interconnection transformational structure, transmission line ghost effect and dorsal pore ghost effect.

3. the De-embedding method of compound semiconductor device according to claim 2, is characterized in that, the described ghost effect according to producing, and removes ghost effect step by step from outside to inside, specifically comprises:

By the cascade connection of matrix, remove metal pad ghost effect, the ghost effect of metal interconnection transformational structure, transmission line ghost effect and dorsal pore ghost effect successively from outside to inside, go to be embedded into intrinsic device input/output port with reference to plane, thus obtain the intrinsic parameters of compound semiconductor radio-frequency devices.

4. the De-embedding method of compound semiconductor device according to any one of claim 1 to 3, is characterized in that, described compound semiconductor device is the compound semiconductor field effect transistor with radiofrequency characteristics.

5. the De-embedding method of the compound semiconductor device according to Claims 2 or 3, it is characterized in that, described metal pad ghost effect, it is the ghost effect that the metal pad for realizing probes touch produces, comprise the fl transmission line of two metal pads and the ghost effect of backward open circuited transmission line generation, and the ghost effect that the crosstalk capacitance between metal pad produces.

6. the De-embedding method of the compound semiconductor device according to Claims 2 or 3, it is characterized in that, the ghost effect of described metal interconnection transformational structure, for the ghost effect of metal pad to the metal interconnection transformational structure generation excessive gently of transmission line, metal interconnection transformational structure is made up of lump LC equivalent structure, and the crosstalk capacitance between metal interconnection transformational structure is integrated in other two crosstalk capacitance and goes.

7. the De-embedding method of the compound semiconductor device according to Claims 2 or 3, it is characterized in that, described transmission line ghost effect, being the ghost effect that the transmission line exported for connecting intrinsic device produces, comprising the ghost effect of both sides transmission line and the generation of crosstalk capacitance between the two.

8. the De-embedding method of the compound semiconductor device according to Claims 2 or 3, is characterized in that, described dorsal pore ghost effect, is the ghost effect that the dorsal pore for realizing common source ground connection produces.