阅读说明：本技术 一种稳定带隙电压的方法 (Method for stabilizing band gap voltage ) 是由 庞微 封晶 蒋晓宏 戴锦华 于 2020-04-27 设计创作，主要内容包括：本发明公开一种稳定带隙电压的方法,其主要先提供一第一布局图案对应一第一电压,然后降低第一布局图案的临界线宽以产生一第二布局图案对应一第二电压,接着将第二电压及一目标电压进行比对,再输出第二布局图案至一光掩模,其中第一布局图案以及第二布局图案包含多晶硅电阻图案。(The invention discloses a method for stabilizing band gap voltage, which mainly provides a first layout pattern corresponding to a first voltage, then reduces the critical line width of the first layout pattern to generate a second layout pattern corresponding to a second voltage, then compares the second voltage with a target voltage, and outputs the second layout pattern to a photomask, wherein the first layout pattern and the second layout pattern comprise polysilicon resistor patterns.)

1. A method of stabilizing a bandgap voltage, comprising:

providing a first layout pattern corresponding to a first voltage;

reducing the critical line width of the first layout pattern to generate a second layout pattern corresponding to a second voltage;

comparing the second voltage with a target voltage; and

outputting the second layout pattern to the photomask.

2. The method of claim 1, wherein the first layout pattern and the second layout pattern comprise polysilicon resistor patterns.

3. The method of claim 1, further comprising reducing the width of the first layout pattern to generate the second layout pattern.

4. The method of claim 3, further comprising reducing the width of the first layout pattern to generate the second layout pattern and a third layout pattern.

5. The method of claim 4, further comprising reducing the width of the first layout pattern by 2% to 4% to generate the second layout pattern.

6. The method of claim 4, further comprising reducing the width of the first layout pattern by 4% to 6% to generate the third layout pattern.

7. The method of claim 4, wherein the second layout pattern corresponds to the second voltage and the third layout pattern corresponds to a third voltage.

8. The method of claim 7, further comprising comparing the third voltage to the target voltage.

9. The method of claim 4, further comprising reducing the width of the first layout pattern to generate the second layout pattern, the third layout pattern and a fourth layout pattern.

10. The method of claim 9, further comprising reducing the width of the first layout pattern by 6% to 8% to generate the fourth layout pattern.

Technical Field

The invention relates to a method for stabilizing the voltage of a band-gap reference circuit.

Background

In the current circuit design field, a Bandgap Reference (Bandgap Reference) circuit is a commonly used predetermined voltage providing circuit, and its advantages include low power consumption, stable output voltage, etc. The common bandgap reference circuit adjusts the voltage across the transistor interface and the current across the internal impedance, so that the reference voltage provided by the common bandgap reference circuit is not easily affected by the temperature change. Therefore, the bandgap reference circuit can be used as a voltage supply source of a voltage stabilizing circuit.

Generally, the design of the conventional bandgap reference circuit mainly has three verification parameters in the technical parameter analysis, which include verification methods such as resistance comparison (resistance matching), I/O device comparison (I/O device matching), and bipolar transistor comparison (BJT matching). However, it is often found that the bandgap reference circuit only reaches 1.11 volts when performing product verification, which is 90 mv less than 1.2 volts of the model target. Although the bandgap voltage circuit design of the client is a new design, since the design completely conforms to the standard of the current 40 nm low power manufacturing process and all passes the comparison of the three verification parameters, it is an important issue to provide a new solution to make the voltage of the bandgap reference circuit reach the model target in addition to the three verification methods.

Disclosure of Invention

The invention discloses a method for stabilizing band gap voltage, which comprises the steps of providing a first layout pattern corresponding to a first voltage, reducing the critical line width of the first layout pattern to generate a second layout pattern corresponding to a second voltage, comparing the second voltage with a target voltage, and outputting the second layout pattern to a photomask.

According to an embodiment of the present invention, the first layout pattern and the second layout pattern include polysilicon resistor patterns.

According to an embodiment of the present invention, the method further includes reducing the width of the first layout pattern to generate a second layout pattern.

According to an embodiment of the present invention, the method further includes reducing the width of the first layout pattern to generate a second layout pattern and a third layout pattern.

According to an embodiment of the present invention, the method further includes reducing the width of the first layout pattern by 2% to 4% to generate a second layout pattern.

According to an embodiment of the present invention, the method further includes reducing the width of the first layout pattern by 4% to 6% to generate a third layout pattern.

According to an embodiment of the present invention, the second layout pattern corresponds to a second voltage and the third layout pattern corresponds to a third voltage.

According to an embodiment of the present invention, the method further comprises comparing the third voltage with the target voltage.

According to an embodiment of the present invention, the method further includes reducing the width of the first layout pattern to generate a second layout pattern, a third layout pattern and a fourth layout pattern.

According to an embodiment of the present invention, the method further includes reducing the width of the first layout pattern by 6% to 8% to generate the fourth layout pattern.

Drawings

FIG. 1 is a flow chart of stabilizing bandgap voltage according to one embodiment of the present invention;

fig. 2 is a schematic diagram illustrating a method of adjusting a layout pattern to stabilize a bandgap voltage by using a compensation (sizing) method.

Description of the main elements

12 first layout pattern

14 polysilicon resistor pattern

16 contact pad

18 second layout pattern

20 third layout Pattern

22 fourth layout Pattern

24 the fifth layout pattern

26 sixth layout Pattern

28 seventh layout Pattern

30 eighth layout Pattern

101 to 104, step

L₁A first length

L₂The second length

L₃The third length

L₄The fourth length

L₅The fifth length

L₆The sixth length

L₇The seventh length

L₈The eighth length

W₁A first width

W₂The second width

W₃The third width

W₄The fourth width

W₅The fifth width

W₆The sixth width

W₇The seventh width

W₈The eighth width

Detailed Description

Referring to fig. 1 to 2, fig. 1 is a flow chart illustrating a bandgap voltage stabilization method according to an embodiment of the invention, and fig. 2 is a schematic diagram illustrating a bandgap voltage stabilization method by adjusting a layout pattern in a compensation (sizing) manner. As shown in fig. 1-2, first, step 101 is performed to generate a photomask design Data or the first layout pattern 12 of fig. 2 according to a circuit design of an integrated circuit, such as a bandgap reference circuit, wherein the photomask design Data may have a variety of formats, such as but not limited to, a format of a Structured Information standard (OASIS), a Graphic Data System format (GDS), and a Graphic Data System format second edition (GDSII). The photomask design data may be recorded in various forms, such as but not limited to text files (WORD or TXT), spreadsheet (EXCEL), Portable Document Format (PDF), electronic mail (Email), facsimile (Fax), and even in a picture or image format. The foregoing is by way of example only and is not intended as a limitation upon the present invention.

In the present embodiment, the first layout pattern 12 is preferably a predetermined layout pattern provided by the foundry client, which preferably includes the GDS file and preferably corresponds to a polysilicon resistor pattern in the subsequent semiconductor manufacturing process. More specifically, the first layout pattern 12 includes a substantially rectangular polysilicon resistor pattern 14 and contact pads 16 disposed on two sides of the polysilicon resistor pattern, wherein the first layout pattern 12 or the polysilicon resistor pattern 14 includes a first width W₁And a first length L₁And the first layout pattern 12 preferably has a first voltage after measurement.

Then, in step 102, the critical line width of the first layout pattern 12 is reduced to generate at least another layout pattern, such as the second layout pattern 18, the third layout pattern 20, the fourth layout pattern 22, the fifth layout pattern 24, the sixth layout pattern 26, the seventh layout pattern 28, and the eighth layout pattern 30. In view of the above, the stage is preferably the first stage provided by the original factoryA layout pattern 12 is subjected to a reducing compensation (reducing) step or more specifically, a reduction of the predetermined first width W of the first layout pattern 12₁So as to generate one or more layout patterns such as the aforementioned second layout pattern 18, third layout pattern 20, fourth layout pattern 22, fifth layout pattern 24, sixth layout pattern 26, seventh layout pattern 28 and eighth layout pattern 30, wherein each generated layout pattern includes the polysilicon resistor pattern 14 and the contact pads 16 disposed on both sides of the polysilicon resistor pattern 14, and the range of the reduction compensation in the second layout pattern 18 to the eighth layout pattern 20 is gradually decreased according to the manufacturing process or the product requirement.

For example, the second layout pattern 18 is generated to include the first width W₁A reduced second width W₂And a second length L₂Wherein the second layout pattern 18 or more specifically the second width W of the second layout pattern 18 is generated₂The method preferably includes reducing the first width W of the first layout pattern₁2% to 4% of the first width W, the polysilicon resistor pattern 14 except the contact pad 16 in the second layout pattern 18 is formed from the original first width W₁Reduced to a second width W₂. In the present embodiment, the second layout pattern 18 has the original first width W₁The distance for performing the single-sided reduction is preferably between 20 nm and 30 nm or more preferably about 25 nm, or the second width W of the second layout pattern 18 as a whole₂The first width W is larger than the original first layout pattern 12₁Both sides are reduced in total to a range of about 50 nanometers. It should be noted that, since the overall width of the second layout pattern 18 is reduced, the resistance and the voltage corresponding to the second layout pattern 18 are increased accordingly, and the second layout pattern 18 has a second voltage after the above-mentioned reduction compensation and measurement.

Similar to the second layout pattern 18, the generated third layout pattern 20 includes the first width W₁A reduced third width W₃And a third length L₃Wherein a third width W of the third layout pattern 20 is generated₃Preferably, the method includes reducing the first width W of the first layout pattern 12₁4 to 6 percent ofThe polysilicon resistor patterns 14 except the contact pads 16 in the third layout pattern 20 have the original first width W₁Reduced to a third width W₃. In the present embodiment, the third layout pattern 20 has the original first width W₁The distance for performing the single-sided reduction is preferably between 45 nm and 55 nm or more preferably about 50 nm, or the third width W of the third layout pattern as a whole₃A first width W compared with the original first layout pattern₁Both sides are reduced in total to a range of about 100 nanometers. Similarly, since the overall width of the third layout pattern 20 is reduced, it means that the resistance and the voltage corresponding to the third layout pattern 20 are increased, and the third layout pattern 20 has a third voltage after the above-mentioned reduction compensation and measurement.

Similar to the third layout pattern 20, the fourth layout pattern 22 is generated to include the first width W₁A reduced fourth width W₄And a fourth length L₄Wherein a fourth width W of the fourth layout pattern 22 is generated₄Preferably, the method includes reducing the first width W of the first layout pattern 12₁6% to 8%, the polysilicon resistor patterns 14 except the contact pads 16 in the fourth layout pattern 22 are formed from the original first width W₁Reduced to a fourth width W₄. In the present embodiment, the fourth layout pattern 22 has the original first width W₁The distance for performing the single-sided reduction is preferably between 70 nm and 80 nm or more preferably about 75 nm, or the fourth width W of the fourth layout pattern 22 as a whole₄The first width W is larger than the original first layout pattern 12₁Both sides are reduced in total to a range of about 150 nanometers. Similarly, since the overall width of the fourth layout pattern 22 is reduced, it means that the resistance and the voltage corresponding to the fourth layout pattern 22 are increased, and the fourth layout pattern 22 has a fourth voltage after the above-mentioned reduction compensation and measurement.

Like the fourth layout pattern 22, the fifth layout pattern 24 is generated to include the aforementioned first width W₁A reduced fifth width W₅And a fifth length L₅Wherein a fifth width W of the fifth layout pattern 24 is generated₅Preferably, the method includes decreasing the firstFirst width W of layout pattern 12₁8% to 10% of the first pattern 24, the polysilicon resistor patterns 14 except the contact pads 16 in the fifth layout pattern 24 have the original first width W₁Reduced to a fifth width W₅. In the present embodiment, the fifth layout pattern 24 has the original first width W₁The distance for performing the single-sided reduction is preferably between 95 nm and 105 nm or more preferably about 100 nm, or the fifth width W of the fifth layout pattern 24 as a whole₅The first width W is larger than the original first layout pattern 12₁Both sides are reduced in total to a range of about 200 nanometers. Similarly, since the overall width of the fifth layout pattern 24 is reduced, it means that the resistance and the voltage corresponding to the fifth layout pattern 24 are increased, and the fifth layout pattern 24 has a fifth voltage after the above-mentioned reduction compensation and measurement.

Similar to the fifth layout pattern 24, the generated sixth layout pattern 26 includes the aforementioned first width W₁A reduced sixth width W₆And a sixth length L₆Wherein a sixth width W of the sixth layout pattern 26 is generated₆Preferably, the method includes reducing the first width W of the first layout pattern 12₁10% to 12% of the first layout pattern 26, the polysilicon resistor pattern 14 except the contact pad 16 in the sixth layout pattern 26 has the original first width W₁Reduced to a sixth width W₆. In the present embodiment, the sixth layout pattern 26 has the original first width W₁The distance for performing the single-sided reduction is preferably between 120 nm and 130 nm or more preferably about 125 nm, or the sixth width W of the sixth layout pattern 26 as a whole₆The first width W is larger than the original first layout pattern 12₁Both sides are reduced in total to a range of about 250 nanometers. Similarly, since the overall width of the sixth layout pattern 26 is reduced, it means that the resistance and the voltage corresponding to the sixth layout pattern 26 are increased, and the sixth layout pattern 26 has a sixth voltage after the above-mentioned reduction compensation and measurement.

Similar to the sixth layout pattern 26, the seventh layout pattern 28 is generated to include the first width W₁A reduced seventh width W₇And a seventh length L₇Wherein a seventh layout is generatedSeventh width W of pattern 28₇Preferably, the method includes reducing the first width W of the first layout pattern 12₁12% to 14%, the polysilicon resistor patterns 14 except the contact pads 16 in the seventh layout pattern 28 have the original first width W₁Reduced to a seventh width W₇. In the present embodiment, the seventh layout pattern 28 has the original first width W₁The distance for performing the single-sided reduction is preferably between 145 nm and 155 nm or more preferably about 150 nm, or the seventh width W of the seventh layout pattern 28 as a whole₇The first width W is larger than the original first layout pattern 12₁Both sides are reduced in total to a range of about 300 nanometers. Similarly, since the entire width of the seventh layout pattern 28 is reduced, it means that the resistance and the voltage corresponding to the seventh layout pattern 28 are increased, and the seventh layout pattern 28 has a seventh voltage after the measurement and compensation of the decrease.

Similar to the seventh layout pattern 28, the eighth layout pattern 30 is generated to include the first width W₁A reduced eighth width W₈And an eighth length L₈Wherein an eighth width W of the eighth layout pattern 30 is generated₈Preferably, the method includes reducing the first width W of the first layout pattern 12₁14% to 16%, the polysilicon resistor patterns 14 except the contact pads 16 in the eighth layout pattern 30 have the original first width W₁Reduced to an eighth width W₈. In the present embodiment, the eighth layout pattern 30 has the original first width W₁The distance for performing the single-sided reduction is preferably between 170 nm and 180 nm or more preferably about 175 nm, or the eighth width W of the eighth layout pattern 30 as a whole₈The first width W is larger than the original first layout pattern 12₁Both sides are reduced in total to a range of about 350 nanometers. Similarly, since the overall width of the eighth layout pattern 30 is reduced, it means that the resistance and the voltage corresponding to the eighth layout pattern 30 are increased, and the eighth layout pattern 30 has an eighth voltage after the above-mentioned reduction compensation and measurement.

Then, step 103 is performed to compare voltages corresponding to the layout patterns generated by reducing the critical line width of the first layout pattern 12, including voltages corresponding to the second, third, fourth, fifth, sixth, seventh and eighth layout patterns 18, 20, 22, 24, 26, 28 and 30 after measurement, for example, the second voltage of the second layout pattern 18, the third voltage of the third layout pattern 20, the fourth voltage of the fourth layout pattern 22, the fifth voltage of the fifth layout pattern 24, the sixth voltage of the sixth layout pattern 26, the seventh voltage of the seventh layout pattern 28 and the eighth voltage of the eighth layout pattern 30, with the target voltage, and thereby determine which voltage corresponding to the layout pattern generated by the step of reducing and compensating (sizing down) is closest to the target voltage. In the present embodiment, the target voltage is preferably 1.2 volts of the model target (model target) and the voltages of the fifth layout pattern 24 and the sixth layout pattern 26 are closest to the target voltage after comparison, so that the two sets of layout patterns are preferably selected as the target patterns of the subsequent photomask.

Then, according to the manufacturing process requirements, correction steps such as Optical Proximity Correction (OPC), Process Rule Check (PRC), and/or optical rule check (LRC) may be performed on each layout pattern, and finally, step 104 is performed to output the corrected layout pattern and manufacture a photomask to prepare a desired image pattern on a subsequent wafer.

From the practical process, the present invention can first input a circuit layout diagram including the first layout pattern 12 provided by the factory client in the computer system, then reduce the critical line width of the first layout pattern 12 and generate a plurality of layout patterns such as the second layout pattern 18, the third layout pattern 20, the fourth layout pattern 22, the fifth layout pattern 24, the sixth layout pattern 26, the seventh layout pattern 28 and the eighth layout pattern 30 of the previous embodiment, and then output the eight layout patterns to a photomask and form eight patterns composed of, for example, polysilicon on a semiconductor substrate composed of a silicon wafer or a silicon substrate by using the photomask, and the prepared first batch of patterns are preferably used as test keys (testkeys). Then, eight polysilicon patterns formed on the semiconductor substrate according to the eight layout patterns are actually measured to obtain corresponding resistance values and voltages, the voltages corresponding to the patterns are compared with a target voltage, the pattern closest to the target voltage is selected as a target pattern (for example, the five layout patterns 24 and/or the sixth layout pattern 26 in the foregoing embodiment), and then the first layout pattern 12 in the circuit layout provided by the customer is corrected according to the target pattern or directly replaces the first layout pattern 12 by OPC in the computer system and then output again on another photomask to prepare a second batch of finally required patterns. In addition, according to other embodiments of the present invention, the step of fabricating the layout pattern on the semiconductor substrate may be omitted, and the voltage comparison is directly performed in a computer system by using an analog method, and the OPC is used to correct the layout pattern and then output the corrected layout pattern to a photomask to fabricate the actual pattern on the semiconductor substrate.

As described above, when performing product verification, the current bandgap reference circuit often finds that the designed circuit voltage only reaches 1.11 volts, which is 90 mv less than 1.2 volts of the model target (model target). Because the current verification methods such as resistance matching, I/O device matching, bipolar transistor matching, and the like cannot solve the problem of insufficient or unstable voltage, the present invention provides a first layout pattern or more specifically a preset layout pattern provided by the factory, and then reduces the critical line width of the first layout pattern to generate a plurality of layout patterns such as the second layout pattern, the third layout pattern, the fourth layout pattern, the fifth layout pattern, the sixth layout pattern, the seventh layout pattern, and the eighth layout pattern in the foregoing embodiments, wherein each layout pattern includes a polysilicon resistance pattern in the semiconductor manufacturing process and has a corresponding voltage after being measured. Because each layout pattern is subjected to reduction compensation in different degrees according to the preset layout pattern provided by the original factory client, the resistance and the voltage measured by each layout pattern after compensation are improved in different degrees better, and further the layout pattern closer to the model target can be obtained after comparison to serve as the output of a subsequent photomask and achieve the purpose of stabilizing the voltage of the bandgap reference circuit.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in the claims of the present invention should be covered by the present invention.