CN106706172B - Preparation method of pressure sensor - Google Patents
Preparation method of pressure sensor Download PDFInfo
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- CN106706172B CN106706172B CN201510770552.5A CN201510770552A CN106706172B CN 106706172 B CN106706172 B CN 106706172B CN 201510770552 A CN201510770552 A CN 201510770552A CN 106706172 B CN106706172 B CN 106706172B
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Abstract
The preparation method of the pressure sensor comprises the following steps: providing a semiconductor substrate; forming a pressure sensing layer on the surface of the semiconductor substrate, forming a cavity between the pressure sensing layer and the semiconductor substrate, wherein a first opening is formed in the pressure sensing layer on the cavity; forming a sacrificial layer, wherein the sacrificial layer covers the pressure sensing layer and fills part of the first opening; etching the sacrificial layer, and reserving an annular sacrificial layer close to the edge of the cavity; forming a protective layer, wherein the protective layer covers the pressure sensing layer; etching the protective layer, removing the protective layer on the sacrificial layer, and forming a second opening in the protective layer, wherein the second opening is a pressure sensing area of the pressure sensor; and removing the sacrificial layer and the dielectric layer in the second opening. According to the invention, the pressure sensing layer is prevented from being damaged by etching, impurities are prevented from entering the cavity, and the performance of the pressure sensor is improved.
Description
Technical Field
The invention relates to the technical field of micro-electro-mechanical systems, in particular to a preparation method of a pressure sensor.
Background
Micro Electro Mechanical Systems (MEMS) are a leading-edge research field of multidisciplinary crossing developed on the basis of microelectronic technology, and are a technology for manufacturing micro electromechanical devices by using semiconductor process. Compared with the traditional electromechanical device, the MEMS device has obvious advantages in the aspects of high temperature resistance, small volume and low power consumption. After decades of development, the method has become one of the major scientific and technological fields of world attention, relates to various subjects and technologies such as electronics, machinery, materials, physics, chemistry, biology, medicine and the like, and has wide application prospects.
A pressure sensor is a micro-electro-mechanical system that converts a pressure signal into an electrical signal. The sensor is divided into a piezoresistive pressure sensor and a capacitive pressure sensor according to different working principles. The principle of capacitive pressure sensors is to measure pressure by changing the capacitance between a top electrode and a bottom contact electrode by pressure.
As shown in fig. 1a, the conventional pressure sensor structure includes: the semiconductor substrate 10 is provided with an interconnection layer 11 and a bottom contact electrode 12, the semiconductor substrate 10 is provided with a pressure sensing layer 20, the pressure sensing layer 20 is made of a conductive material, the pressure sensing layer 20 and the semiconductor substrate 10 enclose a cavity 30, so that the bottom contact electrode 20 and the pressure sensing layer 20 located above the bottom contact electrode 12 form a pair of capacitors, when pressure acts on the pressure sensing layer 20, the pressure sensing layer 20 is close to the bottom contact electrode 12, the capacitance value of the capacitor changes, and the pressure can be measured by measuring the change of the capacitance value.
As shown in fig. 1a, an etch stop layer 50 is then formed on the pressure sensitive layer 20, and the removal etch leaves the annular etch stop layer 50 near the edge of the cavity. Thereafter, referring to fig. 1b, a protective layer 40 is formed on the pressure sensing layer 20, the protective layer 40 is etched using the etch stop layer, an opening 41 is formed therein, and the opening 41 serves as a sensing region of the pressure sensor. The prior art step of removing the etch stop layer 50 typically causes damage to the devices within the cavity 30, thereby significantly affecting the performance and yield of the resulting pressure sensor.
Disclosure of Invention
The invention aims to provide a preparation method of a pressure sensor, which solves the problem that the cavity and the pressure sensing layer are damaged in the etching process of an etching stop layer in the prior art.
In order to solve the above technical problem, the present invention provides a method for manufacturing a pressure sensor, including:
providing a semiconductor substrate;
forming a pressure sensing layer on the surface of the semiconductor substrate, forming a cavity between the pressure sensing layer and the semiconductor substrate, wherein the pressure sensing layer on the cavity is provided with at least one first opening;
forming a sacrificial layer, wherein the sacrificial layer covers the pressure sensing layer and fills part of the first opening;
etching the sacrificial layer, and reserving an annular sacrificial layer close to the edge of the cavity;
forming a protective layer, wherein the protective layer covers the pressure sensing layer and the sacrificial layer;
etching the protective layer, removing the protective layer on the sacrificial layer, and forming a second opening in the protective layer, wherein the second opening is used as a pressure sensing area of the pressure sensor;
removing the sacrificial layer in the second opening.
Compared with the prior art, the preparation method of the pressure sensor provided by the invention has the following advantages:
in the preparation method of the pressure sensor, an amorphous carbon layer is formed on the pressure sensing layer, then a circle of amorphous carbon layer on the edge of the cavity is etched and reserved, a protective layer is formed on the amorphous carbon layer and the pressure sensing layer, the amorphous carbon layer fills part of the first opening, and the protective layer completely covers the first opening, so that the amorphous carbon layer is exposed by the etching protective layer, and then the amorphous carbon layer is removed.
Drawings
FIG. 1a is a schematic diagram illustrating a prior art structure for forming an etch stop layer on a pressure-sensitive layer;
FIG. 1b is a schematic diagram of a prior art pressure sensor;
FIG. 2 is a flow chart of a method of making a pressure sensor according to an embodiment of the present invention;
fig. 3 to 9 are schematic views of device structures in a method for manufacturing a pressure sensor according to an embodiment of the present invention.
Detailed Description
The method of making the pressure sensor of the present invention will now be described in more detail with reference to the schematic drawings, in which preferred embodiments of the invention are shown, it being understood that one skilled in the art may modify the invention herein described while still achieving the advantageous effects of the invention. Accordingly, the following description should be construed as broadly as possible to those skilled in the art and not as limiting the invention.
In the interest of clarity, not all features of an actual implementation are described. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific details must be set forth in order to achieve the developer's specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art.
The invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.
The flow chart of the preparation method of the detection sensor provided by the invention is shown in fig. 2, and the preparation method specifically comprises the following steps:
step S11, providing a semiconductor substrate;
step S12, forming a pressure sensing layer on the surface of the semiconductor substrate, forming a cavity between the pressure sensing layer and the semiconductor substrate, wherein the pressure sensing layer on the cavity has at least one first opening therein;
step S13, forming a sacrificial layer covering the pressure-sensitive layer and filling the first opening;
step S14, etching the sacrificial layer, and reserving an annular sacrificial layer close to the edge of the cavity;
step S15, forming a protective layer, wherein the protective layer covers the sacrificial layer and the rest pressure induction layer;
step S16, etching the protection layer, and forming a second opening in the protection layer, wherein the second opening exposes the sacrificial layer, and the second opening is used as a pressure sensing area of the pressure sensor;
step S17, removing the sacrificial layer in the second opening and removing the sacrificial layer in the second opening with the dielectric layer.
The following describes a method for manufacturing a pressure sensor according to the present invention with reference to fig. 3 to 9, where fig. 3 to 9 are schematic diagrams of device structures in the method for manufacturing a pressure sensor according to an embodiment of the present invention.
First, step S11 is performed, as shown in fig. 3, a semiconductor substrate 100 is provided, where the semiconductor substrate 100 includes a substrate 110 having a control circuit (not shown in the figure), and an interlayer dielectric layer 120 located on the substrate 110, the interlayer dielectric layer 120 has an interconnect structure 121 and a bottom contact electrode 122 therein, and the thickness of the bottom contact electrode 122 is 0.5 μm to 4.0 μm. In addition, other device structures, such as amplifiers, digital-to-analog converters, analog and/or digital processing circuits, interface circuits, and the like, may be formed in the semiconductor substrate 100, and the methods for forming these device structures may be CMOS processes. The interconnect structure 121 may include plugs and interconnect lines, and the specific structure thereof needs to be determined according to actual situations. The material of the bottom contact electrode 122 is selected from one of aluminum, titanium, zinc, silver, gold, copper, tungsten, cobalt, nickel, tantalum, platinum, or any combination thereof.
Next, step S12 is performed, as shown in fig. 3 and 4, to form a pressure-sensitive layer 300 on the surface of the semiconductor substrate 100, a cavity 320 is formed between the pressure-sensitive layer 300 and the semiconductor substrate 100, the pressure-sensitive layer 300 on the cavity 320 has at least one first opening 310 therein, and as shown in fig. 3 and 4, the step of forming the cavity 320 on the semiconductor substrate 100 includes the following steps:
referring to fig. 3, a sacrificial layer is formed on the semiconductor substrate 100, in this embodiment, the sacrificial layer is, for example, amorphous carbon, and then, a part of the amorphous carbon is removed by using photolithography and etching processes, and the remaining amorphous carbon on the bottom contact electrode plate 122 is the sacrificial layer 200. The method of forming amorphous carbon is a Plasma Enhanced Chemical Vapor Deposition (PECVD) process. The parameters of the plasma enhanced chemical vapor deposition process are as follows: the temperature range is 250-420 ℃, the air pressure range is 1-20 torr, the RF power range is 800-2000W, and the reaction gas comprises: c3H6And He, the flow rate of the reaction gas is 1000 sccm-4200 sccm, wherein C3H6The volume ratio of He to He is 2: 1-10: 1.
With continued reference to fig. 3, the stress-inducing layer 300 is formed on the semiconductor substrate 100, and the stress-inducing layer 300 covers the top surface, the side surface, and a portion of the semiconductor substrate 100 of the sacrificial layer 200. The pressure-sensitive layer 300 is also electrically connected to the interconnect structure 121. In this embodiment, the pressure-sensitive layer is Si1-xGexX has a value of between 0.5 and 0.8, Si1-xGexThe thickness of (A) is 0.5 to 3.0 μm.
Referring to fig. 4, the first opening 310 is formed in the pressure-sensitive layer 300, and the first opening 310 exposes the sacrificial layer 200.
With continued reference to FIG. 4, the sacrificial layer 200 is removed through the first opening 310, forming the cavity 320 between the pressure sensing layer 300 and the bottom contact electrode 122. The method of removing the sacrificial layer 200 is an ashing process, in which amorphous carbon is etched by using oxygen plasma, and the amorphous carbon and oxygen generate carbon dioxide gas, which is volatilized from the first opening 310.
Then, in step S13, referring to fig. 5, a sacrificial layer 410 is formed on the pressure-sensitive layer 300, for example, the material of the sacrificial layer may be amorphous carbon or a photoresist material. Similarly, the method of depositing the amorphous carbon layer 410 is the same as the method of depositing the sacrificial layer 200, and thus the detailed description thereof is omitted. In this embodiment, the thickness of the amorphous carbon layer 410 is, for example
Moreover, since the amorphous carbon layer 410 has poor sealing capability, the amorphous carbon layer 410 only fills a portion of the first opening 310, and it is difficult to completely fill the first opening 310.
Next, in step S14, with continued reference to fig. 5, a dielectric layer 420 is formed on the amorphous carbon layer, the material of the dielectric layer 420 may be silicon nitride or silicon oxide, and the forming process may be a process for forming silicon oxide and silicon nitride, which is well known in the art. This step is optional and may not form a dielectric layer in other embodiments.
Next, step S14 is performed to continue to refer to fig. 5, in which amorphous carbon layer 410 is etched, and a circle of amorphous carbon layer on the edge of the cavity is remained. In this embodiment, a dielectric layer 420 is formed on the amorphous carbon layer, the material of the dielectric layer may be silicon dioxide or silicon nitride, a mask pattern 600 is formed on the dielectric layer by photolithography, the mask pattern masks a circle of the dielectric layer on the edge of the cavity formed by the pressure sensing layer and the semiconductor substrate, and the dielectric layer on the rest positions is exposed, referring to fig. 6, the dielectric layer is etched by plasma etching, and then the exposed amorphous carbon layer is removed by ashing, and a circle of the amorphous carbon layer and the dielectric layer on the edge of the cavity are retained.
Proceeding to step S15, referring to fig. 7, a protection layer 700 is deposited on the semiconductor substrate 100, wherein the protection layer 700 covers the pressure-sensitive layer 300 and the amorphous carbon layer. The protection layer 700 may be, for example, a dielectric such as silicon oxide or silicon nitride, and the protection layer 700 is used for protecting the pressure sensor subsequently, and preventing the pressure sensor from being contaminated.
Next, step S16 is performed, referring to fig. 8, the protection layer 700 is etched, the protection layer 700 on the amorphous carbon layer 410 is removed, and a second opening 710 exposing the amorphous carbon layer is formed in the protection layer 700. When the protection layer 700 is etched, the amorphous carbon layer 410 serves as an etch stop layer for the pressure-sensitive layer 300, protecting the pressure-sensitive layer 300. In the invention, the amorphous carbon layer 410 is used as an etching stop layer, so that the pressure sensing layer and the cavity can be protected, and the performance of the pressure sensor can be improved.
Finally, step S17 is performed, and referring to fig. 9, the dielectric layer 420 and the amorphous carbon layer 310 are completely removed. The process of removing the amorphous carbon layer 310 is well known to those skilled in the art and will not be described herein.
In summary, the present invention provides a method for manufacturing a pressure sensor, which includes forming an amorphous carbon layer on a pressure sensing layer, and forming a dielectric layer on the amorphous carbon layer, wherein the amorphous carbon layer fills a portion of the first opening, and the dielectric layer completely covers the first opening. In the process of selectively etching the dielectric layer by taking the patterned photoresist as a mask, the amorphous carbon layer protects the pressure induction layer from being damaged by plasma etching. And then, in the process of etching the amorphous carbon layer by taking the dielectric layer as a mask, the adopted oxygen plasma can not damage the pressure induction layer. In addition, in the process of etching the amorphous carbon layer, the patterned photoresist on the dielectric layer is removed, so that the subsequent process of cleaning the patterned photoresist is avoided, and the cavity is prevented from being formed by impurities such as cleaning solution and the like.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (5)
1. A method of making a pressure sensor, comprising:
providing a semiconductor substrate;
forming a pressure sensing layer on the surface of the semiconductor substrate, forming a cavity between the pressure sensing layer and the semiconductor substrate, wherein the pressure sensing layer on the cavity is provided with at least one first opening, and the cavity is formed by removing amorphous carbon in the cavity through the first opening;
forming a sacrificial layer, wherein the material of the sacrificial layer is amorphous carbon, the sacrificial layer covers the pressure sensing layer and fills part of the first opening;
etching the sacrificial layer, and reserving an annular sacrificial layer close to the edge of the cavity;
forming a protective layer, wherein the protective layer covers the pressure sensing layer and the sacrificial layer;
etching the protective layer, removing the protective layer on the sacrificial layer, and forming a second opening in the protective layer, wherein the second opening is used as a pressure sensing area of the pressure sensor;
removing the sacrificial layer in the second opening;
before the step of etching the sacrificial layer, the method further comprises the following steps:
forming a dielectric layer on the sacrificial layer, wherein the dielectric layer covers the sacrificial layer and completely covers the first opening;
etching the dielectric layer and reserving a circle of dielectric layer at the edge of the cavity;
etching the sacrificial layer by taking the dielectric layer as a mask;
after the protective layer is etched, the method further comprises the following steps:
removing the dielectric layer in the second opening;
the step of removing the sacrificial layer and the dielectric layer in the second opening includes:
removing the dielectric layer by plasma etching;
and ashing to remove the sacrificial layer.
2. The method of claim 1, wherein the semiconductor substrate comprises a substrate with a control circuit, an interlayer dielectric, and an interconnect structure with a bottom contact electrode, wherein the pressure sensing layer is electrically connected to the interconnect structure, and the cavity is formed between the pressure sensing layer and the bottom contact electrode.
3. The method of manufacturing a pressure sensor according to claim 1, wherein the sacrificial layer is an amorphous carbon layer.
4. The method of claim 1, wherein the process for forming the amorphous carbon layer is a Plasma Enhanced Chemical Vapor Deposition (PECVD) process, and the PECVD process has parameters: the temperature range is 250-420 ℃, the air pressure range is 1-20 torr, the RF power range is 800-2000W, and the reaction gas comprises: c3H6And He, the flow rate of the reaction gas is 1000 sccm-4200 sccm, wherein C3H6: the volume ratio range of He is 2: 1-10: 1.
5. the method of manufacturing a pressure sensor according to claim 4, wherein the dielectric layer is made of: silicon nitride or silicon oxide.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101743626A (en) * | 2007-06-27 | 2010-06-16 | 桑迪士克公司 | Method for fabricating a 3-D integrated circuit using a hard mask of silicon-oxynitride on amorphous carbon |
| CN102328904A (en) * | 2011-09-30 | 2012-01-25 | 上海丽恒光微电子科技有限公司 | Method for forming microelectro mechanical system (MEMS) device |
| CN102939641A (en) * | 2010-04-30 | 2013-02-20 | 应用材料公司 | Amorphous carbon deposition method for improved stack defectivity |
| CN102515090B (en) * | 2011-12-21 | 2014-11-05 | 上海丽恒光微电子科技有限公司 | Pressure sensor and formation method thereof |
| CN104157574A (en) * | 2014-07-31 | 2014-11-19 | 上海集成电路研发中心有限公司 | Fin structure line top end cutting method for double-pattern finned type effect transistor |
| CN104201101A (en) * | 2014-08-27 | 2014-12-10 | 上海华力微电子有限公司 | Production method for double-contact-hole etching stop layer |
| CN104465508A (en) * | 2014-12-30 | 2015-03-25 | 上海集成电路研发中心有限公司 | Forming method for air gap |
| CN104979273B (en) * | 2014-04-04 | 2018-02-16 | 中芯国际集成电路制造(上海)有限公司 | The method for forming interconnection structure |
-
2015
- 2015-11-12 CN CN201510770552.5A patent/CN106706172B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101743626A (en) * | 2007-06-27 | 2010-06-16 | 桑迪士克公司 | Method for fabricating a 3-D integrated circuit using a hard mask of silicon-oxynitride on amorphous carbon |
| CN102939641A (en) * | 2010-04-30 | 2013-02-20 | 应用材料公司 | Amorphous carbon deposition method for improved stack defectivity |
| CN102328904A (en) * | 2011-09-30 | 2012-01-25 | 上海丽恒光微电子科技有限公司 | Method for forming microelectro mechanical system (MEMS) device |
| CN102515090B (en) * | 2011-12-21 | 2014-11-05 | 上海丽恒光微电子科技有限公司 | Pressure sensor and formation method thereof |
| CN104979273B (en) * | 2014-04-04 | 2018-02-16 | 中芯国际集成电路制造(上海)有限公司 | The method for forming interconnection structure |
| CN104157574A (en) * | 2014-07-31 | 2014-11-19 | 上海集成电路研发中心有限公司 | Fin structure line top end cutting method for double-pattern finned type effect transistor |
| CN104201101A (en) * | 2014-08-27 | 2014-12-10 | 上海华力微电子有限公司 | Production method for double-contact-hole etching stop layer |
| CN104465508A (en) * | 2014-12-30 | 2015-03-25 | 上海集成电路研发中心有限公司 | Forming method for air gap |
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