CN116741874B - Method for preparing contact hole on tellurium-cadmium-mercury infrared detector chip - Google Patents
Method for preparing contact hole on tellurium-cadmium-mercury infrared detector chip Download PDFInfo
- Publication number
- CN116741874B CN116741874B CN202310627281.2A CN202310627281A CN116741874B CN 116741874 B CN116741874 B CN 116741874B CN 202310627281 A CN202310627281 A CN 202310627281A CN 116741874 B CN116741874 B CN 116741874B
- Authority
- CN
- China
- Prior art keywords
- mercury
- passivation film
- etching
- cadmium
- contact hole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 61
- 238000005530 etching Methods 0.000 claims abstract description 115
- 238000002161 passivation Methods 0.000 claims abstract description 115
- 239000000463 material Substances 0.000 claims abstract description 42
- 230000008569 process Effects 0.000 claims abstract description 40
- 229910000661 Mercury cadmium telluride Inorganic materials 0.000 claims abstract description 38
- MCMSPRNYOJJPIZ-UHFFFAOYSA-N cadmium;mercury;tellurium Chemical compound [Cd]=[Te]=[Hg] MCMSPRNYOJJPIZ-UHFFFAOYSA-N 0.000 claims abstract description 38
- 238000001312 dry etching Methods 0.000 claims abstract description 36
- 239000002131 composite material Substances 0.000 claims abstract description 35
- 239000007788 liquid Substances 0.000 claims abstract description 19
- 230000007797 corrosion Effects 0.000 claims abstract description 8
- 238000005260 corrosion Methods 0.000 claims abstract description 8
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 46
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 27
- 229910052786 argon Inorganic materials 0.000 claims description 23
- 239000001257 hydrogen Substances 0.000 claims description 21
- 229910052739 hydrogen Inorganic materials 0.000 claims description 21
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 claims description 20
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 18
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 16
- 239000005083 Zinc sulfide Substances 0.000 claims description 13
- 239000007789 gas Substances 0.000 claims description 13
- 229910052984 zinc sulfide Inorganic materials 0.000 claims description 13
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 claims description 13
- 229920002120 photoresistant polymer Polymers 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- MARUHZGHZWCEQU-UHFFFAOYSA-N 5-phenyl-2h-tetrazole Chemical compound C1=CC=CC=C1C1=NNN=N1 MARUHZGHZWCEQU-UHFFFAOYSA-N 0.000 claims description 9
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 8
- 238000001259 photo etching Methods 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 5
- 239000011248 coating agent Substances 0.000 claims description 4
- 238000000576 coating method Methods 0.000 claims description 4
- 150000002431 hydrogen Chemical class 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 8
- 238000002360 preparation method Methods 0.000 abstract description 8
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 238000009616 inductively coupled plasma Methods 0.000 description 4
- 230000004044 response Effects 0.000 description 4
- 238000001039 wet etching Methods 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- DGJPPCSCQOIWCP-UHFFFAOYSA-N cadmium mercury Chemical compound [Cd].[Hg] DGJPPCSCQOIWCP-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1828—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof the active layers comprising only AIIBVI compounds, e.g. CdS, ZnS, CdTe
- H01L31/1832—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof the active layers comprising only AIIBVI compounds, e.g. CdS, ZnS, CdTe comprising ternary compounds, e.g. Hg Cd Te
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/02002—Arrangements for conducting electric current to or from the device in operations
- H01L31/02005—Arrangements for conducting electric current to or from the device in operations for device characterised by at least one potential jump barrier or surface barrier
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Light Receiving Elements (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
The application relates to the field of infrared detector chip preparation and discloses a method for preparing a contact hole on a tellurium-cadmium-mercury infrared detector chip, which comprises the steps of etching a composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip by a dry etching process according to a contact hole pattern, and removing a second passivation film; the composite passivation film comprises a first passivation film and a second passivation film which are laminated; etching the first passivation film corresponding to the contact hole pattern by using etching solution, and stopping etching until the interface between the first passivation film and the mercury cadmium telluride material; and etching the area of the surface of the tellurium-cadmium-mercury material contacted with the corrosive liquid by using a dry etching process to remove the product generated in the corrosion process of the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, so as to form a contact hole, wherein the etching bias voltage range is 5-10V. The method and the device adopt etching, corrosion and etching modes, so that the depth of the contact hole has high consistency, the electrode in the contact hole has good ohmic contact effect, and simultaneously, the etching damage of the chip is reduced.
Description
Technical Field
The application relates to the field of infrared detector chip preparation, in particular to a method for preparing a contact hole on a tellurium-cadmium-mercury infrared detector chip.
Background
The preparation of the infrared detector chip is the core of the infrared detection technology, the contact hole is a key channel for leading out the electrical property of the pn junction of the infrared detector chip, and the preparation of the contact hole is an important process in the preparation process of the infrared detector chip.
At present, when a contact hole is prepared, a graph is usually prepared on a composite passivation film layer on the surface of a chip by adopting a photoetching process, the composite passivation film layer is etched to the surface of the chip by a dry etching mode to prepare the contact hole, then a metal electrode is prepared in the contact hole to form good ohmic contact, and the electrical property of a pn junction of the chip is led out. When the contact hole is etched, an etching bias voltage needs to be applied, and in order to ensure that the etching is performed smoothly, the etching bias voltage cannot be too small. If the etching bias voltage is controlled very low, the etching agent is difficult to enter the composite passivation film layer, the etching rate is very low, the contact hole preparation process cannot be effectively developed, the etching bias voltage can only be increased, and the etching bias voltage is generally between 50 and 100V. For the tellurium-cadmium-mercury chip, because the tellurium-cadmium-mercury is a relatively sensitive photoelectric material, the increased etching bias is extremely easy to cause etching damage to the tellurium-cadmium-mercury chip, thereby affecting the photoelectric performance of the infrared detector. Meanwhile, the contact hole etching is usually to sequentially etch each layer of film and tellurium cadmium mercury in the composite passivation film layer, the depth uniformity of the contact hole can be influenced by photoetching consistency and uniformity of the composite passivation film layer, and the depth of the contact hole prepared by combining a plurality of factors can generate deviation of 100-200 nm by considering uniformity differences of a dry etching process. Further, as the bottoms of the contact holes are etched to the n-type region of the mercury cadmium telluride chip, different hole depths can cause the difference of metal electrode contact and the difference of n-type regions, thereby leading to poor response consistency of the mercury cadmium telluride infrared detector chip.
Therefore, how to solve the above technical problems should be of great interest to those skilled in the art.
Disclosure of Invention
The purpose of the application is to provide a method for preparing a contact hole on a tellurium-cadmium-mercury infrared detector chip, so that the depth of the contact hole is highly uniform, damage to the tellurium-cadmium-mercury infrared detector chip is reduced, and good ohmic contact between the tellurium-cadmium-mercury infrared detector chip and an electrode in the contact hole is ensured.
In order to solve the above technical problems, the present application provides a method for preparing a contact hole on a mercury cadmium telluride infrared detector chip, comprising:
etching the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip by using a dry etching process according to the contact hole pattern, and removing the second passivation film; the composite passivation film comprises a first passivation film and a second passivation film which are laminated, wherein the first passivation film is positioned on the surface of a mercury cadmium telluride material in the mercury cadmium telluride infrared detector chip;
etching the first passivation film corresponding to the contact hole pattern by using etching solution, and stopping etching until the interface between the first passivation film and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip;
and etching the area, in the tellurium-cadmium-mercury infrared detector chip, where the surface of the tellurium-cadmium-mercury material is in contact with the corrosive liquid by using a dry etching process, and removing a product generated in the corrosion process of the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip to form a contact hole, wherein the etching bias voltage range is 5V-10V.
Optionally, etching the first passivation film corresponding to the contact hole pattern with an etching solution includes:
and corroding the first passivation film corresponding to the contact hole pattern by using a corrosive liquid comprising phosphoric acid, acetic acid, potassium dichromate and water.
Optionally, the proportion of phosphoric acid, acetic acid, potassium dichromate and water in the corrosive liquid is 15 ml-20 ml of phosphoric acid, 5 ml-10 ml of acetic acid, 2 g-5 g of potassium dichromate and 80 ml-100 ml of water.
Optionally, when etching the area where the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip contacts with the etching solution, the etching gas is a mixed gas of argon and hydrogen, and the flow ratio of the argon to the hydrogen is 3:1-4:1.
Optionally, the etching depth range of the area, where the surface of the tellurium-cadmium-mercury material is contacted with the corrosive liquid, of the tellurium-cadmium-mercury infrared detector chip is 50+/-10 nm.
Optionally, when the second passivation film is a zinc sulfide passivation film, etching the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip by using a dry etching process includes:
and etching to remove the second passivation film by using mixed gas of argon and hydrogen under the etching bias voltage range of 120-150V.
Optionally, the flow ratio of the argon to the hydrogen in the argon and hydrogen mixed gas is in the range of 1:1-2:1.
Optionally, before etching the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip by using a dry etching process according to the contact hole pattern, the method further comprises:
preparing the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip;
coating photoresist on the surface of the composite passivation film;
and processing the photoresist by utilizing a photoetching technology to form the contact hole pattern.
The method for preparing the contact hole on the tellurium-cadmium-mercury infrared detector chip comprises the following steps: etching the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip by using a dry etching process according to the contact hole pattern, and removing the second passivation film; the composite passivation film comprises a first passivation film and a second passivation film which are laminated, wherein the first passivation film is positioned on the surface of a mercury cadmium telluride material in the mercury cadmium telluride infrared detector chip; etching the first passivation film corresponding to the contact hole pattern by using etching solution, and stopping etching until the interface between the first passivation film and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip; and etching the area, in the tellurium-cadmium-mercury infrared detector chip, where the surface of the tellurium-cadmium-mercury material is in contact with the corrosive liquid by using a dry etching process, and removing a product generated in the corrosion process of the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip to form a contact hole, wherein the etching bias voltage range is 5V-10V.
Therefore, when the contact hole is prepared, the second passivation film in the composite passivation film is etched by adopting the dry etching process, so that the characteristic of anisotropy of the dry etching process is fully exerted, and the generation of transverse undercut is avoided. And then, etching the first passivation film by adopting etching liquid, wherein the etching is stopped at the interface of the first passivation film and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, and the etching depth has very high consistency, so that the depth of the contact hole has high consistency. The etching solution is in contact with the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, so that the etching solution can react with the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip to generate a plurality of products, the existence of the products can influence the ohmic contact effect of the electrode growing in the contact hole and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, and the dry etching process is used for slightly etching and removing the products generated by etching the surface of the tellurium-cadmium-mercury infrared detector chip, so that the electrode has good ohmic contact effect on the premise of ensuring the depth of the contact hole to have high uniformity, namely, adverse effects on other processes are avoided; meanwhile, the dry etching bias voltage is very low, so that damage to the performance of the tellurium-cadmium-mercury chip is avoided, and the response consistency of the tellurium-cadmium-mercury infrared detector chip is effectively improved.
Drawings
For a clearer description of embodiments of the present application or of the prior art, the drawings that are used in the description of the embodiments or of the prior art will be briefly described, it being apparent that the drawings in the description that follow are only some embodiments of the present application, and that other drawings may be obtained from these drawings by a person of ordinary skill in the art without inventive effort.
FIG. 1 is a flow chart of a method for fabricating contact holes on a mercury cadmium telluride infrared detector chip according to an embodiment of the present application;
fig. 2 to 7 are process flow diagrams of a contact hole preparation method and a process for electrically extracting a pn junction of a mercury cadmium telluride infrared detector chip according to an embodiment of the present application;
in the figure, 1 parts of mercury cadmium telluride material, 2 parts of cadmium telluride passivation film, 3 parts of zinc sulfide passivation film, 4 parts of photoresist and 5 parts of metal electrode layer.
Detailed Description
In order to provide a better understanding of the present application, those skilled in the art will now make further details of the present application with reference to the drawings and detailed description. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.
As described in the background art, the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip is etched by adopting a dry etching process to form a contact hole, the etching bias voltage is generally 50-100V, etching damage is easily caused to the surface of the tellurium-cadmium-mercury infrared detector chip, the uniformity of the depth of the contact hole can be influenced by photoetching uniformity and uniformity of the composite passivation film layer, and in consideration of uniformity difference of the dry etching process, the depth of the contact hole can generally generate larger deviation, and meanwhile, the response uniformity of the tellurium-cadmium-mercury infrared detector chip can be further deteriorated due to different hole depths and etching damage.
In view of this, the present application provides a method for preparing a contact hole on a mercury cadmium telluride infrared detector chip, please refer to fig. 1, which includes:
step S101: etching the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip by using a dry etching process according to the contact hole pattern, and removing the second passivation film; the composite passivation film comprises a first passivation film and a second passivation film which are laminated, wherein the first passivation film is positioned on the surface of a mercury cadmium telluride material in the mercury cadmium telluride infrared detector chip.
The dry etching process may employ an ICP (Inductively Couple Plasma, inductively coupled plasma etching) process.
The contact hole pattern is the pattern formed in the area where the contact hole is needed to be made on the tellurium-cadmium-mercury infrared detector chip.
In this embodiment, pn junctions are already prepared inside the mercury cadmium telluride infrared detector chip. The first passivation film may be a cadmium telluride passivation film with a thickness of 100 nm-300 nm, and the second passivation film may be a zinc sulfide passivation film with a thickness of 200 nm-300 nm.
In the step, the second passivation film is completely removed by dry etching, and the first passivation film can be etched by a small amount or not etched at all.
As an embodiment, when the second passivation film is a zinc sulfide passivation film, etching the composite passivation film on the surface of the mercury cadmium telluride infrared detector chip by using a dry etching process includes:
and etching the second passivation film by using mixed gas of argon and hydrogen under the etching bias voltage range of 120-150V, and immediately etching the zinc sulfide passivation film.
The etching to the interface of the first passivation film and the second passivation film can be monitored by a laser end point provided in the dry etching apparatus.
When etching the second passivation film (zinc sulfide passivation film), the flow ratio of argon to hydrogen in the mixed gas of argon and hydrogen is in the range of 1:1-2:1, for example, the flow ratio of argon to hydrogen may be 1:1,1.5:1,2:1, etc.
Step S102: and corroding the first passivation film corresponding to the contact hole pattern by using corrosive liquid, and stopping corroding until the interface of the first passivation film and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip.
The etching solution has higher selection ratio to the first passivation film, and can stop etching at the interface of the first passivation film and the mercury cadmium telluride material in the mercury cadmium telluride infrared detector chip by controlling the etching time, so that the depth of the contact hole has very high consistency after etching.
As an embodiment, etching the first passivation film corresponding to the contact hole pattern using an etching solution includes:
and corroding the first passivation film corresponding to the contact hole pattern by using a corrosive liquid comprising phosphoric acid, acetic acid, potassium dichromate and water.
The proportion of phosphoric acid, acetic acid, potassium dichromate and water in the corrosive liquid can be 15 ml-20 ml of phosphoric acid, 5 ml-10 ml of acetic acid, 2 g-5 g of potassium dichromate and 80 ml-100 ml of water.
Step S103: and etching the area, in the tellurium-cadmium-mercury infrared detector chip, where the surface of the tellurium-cadmium-mercury material is in contact with the corrosive liquid by using a dry etching process, and removing a product generated in the corrosion process of the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip to form a contact hole, wherein the etching bias voltage range is 5V-10V.
In the step, the etching bias voltage of the dry etching is between 5V and 10V, for example, the etching bias voltage can be 5V, 6V, 7V, 8V, 9V, 10V and the like, the etching bias voltage is very low, and obvious etching damage can not be generated on a tellurium-cadmium-mercury infrared detector chip when the wet etching is used for removing the products generated by the wet etching.
The depth of the contact hole is the thickness delta of the composite passivation film plus the etching depth of the area, which is in contact with corrosive liquid, of the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, the depth consistency of the contact hole is very high, and the depth deviation of the contact hole can be controlled below 20 nm.
As an implementation mode, the etching depth range of the area, which is in contact with the corrosive liquid, of the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip is 50+/-10 nm. That is, the depth of the contact hole is the thickness δ+ (50±10) nm of the composite passivation film.
When etching the area of the tellurium-cadmium-mercury infrared detector chip, which is in contact with the corrosive liquid, the etching gas is a mixed gas of argon and hydrogen, the flow ratio of the argon to the hydrogen is 3:1-4:1, for example, the flow ratio of the argon to the hydrogen is 3:1, 3.5:1, 4:1 and the like.
And removing a product generated by wet corrosion at the interface between the cadmium telluride passivation film and the mercury cadmium telluride chip through the physical etching action of argon.
Because of the existence of ions with strong oxidability in the corrosive liquid, the ions react with mercury cadmium telluride material in the mercury cadmium telluride infrared detector chip to generate some products. The purpose of manufacturing the contact hole is to grow an electrode in the contact hole so as to electrically lead out the tellurium-cadmium-mercury infrared detector chip, if the electrode is directly grown in the contact hole formed after corrosion, an extra parasitic resistance is generated at the interface between metal and tellurium-cadmium-mercury material, and the effect of ohmic contact of the electrode is affected, therefore, the step removes the product on the surface of the inner chip in the contact hole area through slight dry etching, and further ensures that the tellurium-cadmium-mercury infrared detector chip and the electrode form good electrode contact.
In the embodiment, when the contact hole is prepared, the second passivation film in the composite passivation film is etched by adopting a dry etching process, so that the characteristic of anisotropy of the dry etching process is fully exerted, and the generation of transverse undercut is avoided. And then, etching the first passivation film by adopting etching liquid, wherein the etching is stopped at the interface of the first passivation film and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, and the etching depth has very high consistency, so that the depth of the contact hole has high consistency. The etching solution is in contact with the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, so that the etching solution can react with the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip to generate a plurality of products, the existence of the products can influence the ohmic contact effect of the electrode growing in the contact hole and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, and the dry etching process is used for slightly etching and removing the products generated by etching the surface of the tellurium-cadmium-mercury infrared detector chip, so that the electrode has good ohmic contact effect on the premise of ensuring the depth of the contact hole to have high uniformity, namely, adverse effects on other processes are avoided; meanwhile, the dry etching bias voltage is very low, so that damage to the performance of the tellurium-cadmium-mercury chip is avoided, and the response consistency of the tellurium-cadmium-mercury infrared detector chip is effectively improved.
Based on the above embodiments, in one embodiment of the present application, before etching the composite passivation film on the surface of the mercury cadmium telluride infrared detector chip by using a dry etching process according to the contact hole pattern, the method further includes:
preparing the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip;
coating photoresist on the surface of the composite passivation film;
and processing the photoresist by utilizing a photoetching technology to form the contact hole pattern.
The growth process of each passivation film in the composite passivation film is well known to those skilled in the art, and will not be described in detail herein.
In order to ensure the uniformity of the thickness of the photoresist at all positions, the photoresist can be coated on the surface of the composite passivation film in a spin coating mode.
The method for preparing the contact hole and the electrical extraction process of the pn junction of the tellurium-cadmium-mercury infrared detector chip are described in a specific case.
Step 1, sequentially preparing a laminated cadmium telluride passivation film 2 and a zinc sulfide passivation film 3 on the surface of a mercury cadmium telluride material 1 of a mercury cadmium telluride chip, as shown in fig. 2;
step 2, coating photoresist 4 on the surface of a zinc sulfide passivation film 3, and processing the photoresist 4 by utilizing a photoetching technology to form a contact hole pattern, as shown in fig. 3;
step 3, putting the tellurium-cadmium-mercury chip 1 into ICP dry etching equipment, and etching by adopting argon and hydrogen combined gas, wherein the flow rates of the argon and the hydrogen are set to be 1:1, the etching bias voltage is set to be 120-150V, and monitoring and etching to the interface between the zinc sulfide passivation film 3 and the cadmium telluride passivation film 2 through a laser end point equipped by the dry etching equipment, so that the zinc sulfide passivation film 3 in a contact hole is completely etched, as shown in fig. 4;
step 4, putting the tellurium-cadmium-mercury chip 1 etched with the zinc sulfide passivation film 3 in the contact hole into a cadmium telluride etching solution, wherein the etching solution consists of nitric acid, hydrofluoric acid, potassium dichromate and water, the etching solution has a higher selectivity for cadmium telluride, and etching is stopped at the interface of the cadmium telluride passivation film 2 and the tellurium-cadmium-mercury material 1 in the tellurium-cadmium-mercury chip by controlling etching time, as shown in fig. 5;
step 5, putting the tellurium-cadmium-mercury chip into ICP dry etching equipment, and etching by adopting argon and hydrogen combined gas, wherein the flow ratio of the argon and the hydrogen is between 3:1 and 4:1, the etching bias is between 5 and 10V, and removing a product generated by wet etching at the interface between the tellurium-cadmium passivation film 2 and the tellurium-cadmium-mercury material 1 under the physical etching action of the argon, wherein the etching of 50+/-10 nm on the surface of the tellurium-cadmium-mercury material 1 in the tellurium-cadmium-mercury chip can be stopped, as shown in fig. 6;
and 6, after the contact hole is manufactured, directly placing the tellurium-cadmium-mercury chip into electrode deposition equipment, growing a metal electrode layer 5, so that the etched clean tellurium-cadmium-mercury surface can form good contact with metal, avoiding the influence of surface oxidation or impurities, finally removing the metal part covered on the photoresist 4 through a stripping process, completing electrode preparation, and realizing the extraction of the electrical property of the pn junction in the tellurium-cadmium-mercury chip 1, as shown in fig. 7.
In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, so that the same or similar parts between the embodiments are referred to each other.
The method for preparing the contact hole on the tellurium-cadmium-mercury infrared detector chip provided by the application is described in detail above. Specific examples are set forth herein to illustrate the principles and embodiments of the present application, and the description of the examples above is only intended to assist in understanding the methods of the present application and their core ideas. It should be noted that it would be obvious to those skilled in the art that various improvements and modifications can be made to the present application without departing from the principles of the present application, and such improvements and modifications fall within the scope of the claims of the present application.
Claims (8)
1. A method for fabricating a contact hole on a mercury cadmium telluride infrared detector chip, comprising:
etching the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip by using a dry etching process according to the contact hole pattern, and removing the second passivation film; the composite passivation film comprises a first passivation film and a second passivation film which are laminated, wherein the first passivation film is positioned on the surface of a mercury cadmium telluride material in the mercury cadmium telluride infrared detector chip;
etching the first passivation film corresponding to the contact hole pattern by using etching solution, and stopping etching until the interface between the first passivation film and the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip;
etching a region, in which the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip is contacted with the corrosive liquid, by utilizing a dry etching process, removing a product generated in the corrosion process of the surface of the tellurium-cadmium-mercury material in the tellurium-cadmium-mercury infrared detector chip, and forming a contact hole, wherein the etching bias voltage range is 5V-10V; the first passivation film is a cadmium telluride passivation film; the second passivation film is a zinc sulfide passivation film.
2. The method of fabricating a contact hole on a mercury cadmium telluride infrared detector chip according to claim 1 wherein etching the first passivation film corresponding to the contact hole pattern with an etchant comprises:
and corroding the first passivation film corresponding to the contact hole pattern by using a corrosive liquid comprising phosphoric acid, acetic acid, potassium dichromate and water.
3. The method for preparing the contact hole on the tellurium-cadmium-mercury infrared detector chip according to claim 2, wherein the proportion of phosphoric acid, acetic acid, potassium dichromate and water in the corrosive liquid is 15 ml-20 ml, 5 ml-10 ml of acetic acid, 2 g-5 g of potassium dichromate and 80 ml-100 ml of water.
4. The method for manufacturing a contact hole on a mercury cadmium telluride infrared detector chip according to claim 1, wherein when etching the area where the mercury cadmium telluride material surface contacts with the etching solution, the etching gas is a mixed gas of argon and hydrogen, and the flow ratio of the argon to the hydrogen is in the range of 3:1-4:1.
5. The method for manufacturing a contact hole on a mercury cadmium telluride infrared detector chip according to claim 1, wherein the etching depth of the area of the mercury cadmium telluride material surface in contact with the etching solution in the mercury cadmium telluride infrared detector chip is 50+ -10 nm.
6. The method of fabricating a contact hole on a mercury cadmium telluride infrared detector chip according to claim 1 wherein, when the second passivation film is a zinc sulfide passivation film, etching the composite passivation film on the mercury cadmium telluride infrared detector chip surface using a dry etching process comprises:
and etching to remove the second passivation film by using mixed gas of argon and hydrogen under the etching bias voltage range of 120-150V.
7. The method for fabricating a contact hole on a mercury cadmium telluride infrared detector chip according to claim 6 wherein the ratio of the flow rates of argon and hydrogen in the argon and hydrogen mixture is in the range of 1:1 to 2:1.
8. The method for fabricating a contact hole on a mercury cadmium telluride infrared detector chip according to claim 1, further comprising, before etching the composite passivation film on the mercury cadmium telluride infrared detector chip surface by a dry etching process according to the contact hole pattern:
preparing the composite passivation film on the surface of the tellurium-cadmium-mercury infrared detector chip;
coating photoresist on the surface of the composite passivation film;
and processing the photoresist by utilizing a photoetching technology to form the contact hole pattern.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310627281.2A CN116741874B (en) | 2023-05-30 | 2023-05-30 | Method for preparing contact hole on tellurium-cadmium-mercury infrared detector chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310627281.2A CN116741874B (en) | 2023-05-30 | 2023-05-30 | Method for preparing contact hole on tellurium-cadmium-mercury infrared detector chip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116741874A CN116741874A (en) | 2023-09-12 |
| CN116741874B true CN116741874B (en) | 2024-01-09 |
Family
ID=87908959
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310627281.2A Active CN116741874B (en) | 2023-05-30 | 2023-05-30 | Method for preparing contact hole on tellurium-cadmium-mercury infrared detector chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116741874B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4838984A (en) * | 1987-07-16 | 1989-06-13 | Texas Instruments Incorporated | Method for etching films of mercury-cadmium-telluride and zinc sulfid |
| EP0408276A2 (en) * | 1989-07-10 | 1991-01-16 | Texas Instruments Incorporated | Method for dry etching vias in integrated circuit layers |
| JPH10335194A (en) * | 1997-06-03 | 1998-12-18 | Fujitsu Ltd | Semiconductor device and its fabrication |
| JPH11111734A (en) * | 1997-10-01 | 1999-04-23 | Fujitsu Ltd | Method of forming surface protection film |
| CN1741259A (en) * | 2005-09-23 | 2006-03-01 | 中国科学院上海技术物理研究所 | The mask layer and the preparation method that are used for reactive ion etching mercury cadmium telluride micro-mesa array |
| US7115500B1 (en) * | 2004-10-04 | 2006-10-03 | National Semiconductor Corporation | System and method for providing a dry-wet-dry etch procedure to create a sidewall profile of a via |
| CN103887371A (en) * | 2014-03-24 | 2014-06-25 | 北京工业大学 | Technology method for evenly etching InP cardinal plane array device |
| CN106449377A (en) * | 2016-11-25 | 2017-02-22 | 中国科学院上海技术物理研究所 | HgCdTe (mercury cadmium telluride) etching mask capable of automatically controlling forming end point and removal method thereof |
| CN106601609A (en) * | 2016-12-07 | 2017-04-26 | 中国电子科技集团公司第十研究所 | Hgcdte-material low-damage mixed-type dry method etching method |
| CN112117351A (en) * | 2020-09-22 | 2020-12-22 | 北京智创芯源科技有限公司 | Method for leading out electrical properties of mercury cadmium telluride pn junction and detector chip |
| CN115873600A (en) * | 2022-11-28 | 2023-03-31 | 武汉高芯科技有限公司 | Opening corrosive liquid and opening method for cadmium telluride/zinc sulfide double-layer passive film |
-
2023
- 2023-05-30 CN CN202310627281.2A patent/CN116741874B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4838984A (en) * | 1987-07-16 | 1989-06-13 | Texas Instruments Incorporated | Method for etching films of mercury-cadmium-telluride and zinc sulfid |
| EP0408276A2 (en) * | 1989-07-10 | 1991-01-16 | Texas Instruments Incorporated | Method for dry etching vias in integrated circuit layers |
| JPH10335194A (en) * | 1997-06-03 | 1998-12-18 | Fujitsu Ltd | Semiconductor device and its fabrication |
| JPH11111734A (en) * | 1997-10-01 | 1999-04-23 | Fujitsu Ltd | Method of forming surface protection film |
| US7115500B1 (en) * | 2004-10-04 | 2006-10-03 | National Semiconductor Corporation | System and method for providing a dry-wet-dry etch procedure to create a sidewall profile of a via |
| CN1741259A (en) * | 2005-09-23 | 2006-03-01 | 中国科学院上海技术物理研究所 | The mask layer and the preparation method that are used for reactive ion etching mercury cadmium telluride micro-mesa array |
| CN103887371A (en) * | 2014-03-24 | 2014-06-25 | 北京工业大学 | Technology method for evenly etching InP cardinal plane array device |
| CN106449377A (en) * | 2016-11-25 | 2017-02-22 | 中国科学院上海技术物理研究所 | HgCdTe (mercury cadmium telluride) etching mask capable of automatically controlling forming end point and removal method thereof |
| CN106601609A (en) * | 2016-12-07 | 2017-04-26 | 中国电子科技集团公司第十研究所 | Hgcdte-material low-damage mixed-type dry method etching method |
| CN112117351A (en) * | 2020-09-22 | 2020-12-22 | 北京智创芯源科技有限公司 | Method for leading out electrical properties of mercury cadmium telluride pn junction and detector chip |
| CN115873600A (en) * | 2022-11-28 | 2023-03-31 | 武汉高芯科技有限公司 | Opening corrosive liquid and opening method for cadmium telluride/zinc sulfide double-layer passive film |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116741874A (en) | 2023-09-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5801791B2 (en) | Silicon solar cell having emitter with back-etching and method of forming similar solar cell | |
| US9337380B2 (en) | Method for fabricating heterojunction interdigitated back contact photovoltaic cells | |
| TWI455342B (en) | Solar cell with selective emitter structure and manufacturing method thereof | |
| CN102339749B (en) | Metal aluminum bonding pad etching method | |
| JPH0496227A (en) | Etching method | |
| CN112117351B (en) | Method for leading out electrical properties of mercury cadmium telluride pn junction and detector chip | |
| CN116741874B (en) | Method for preparing contact hole on tellurium-cadmium-mercury infrared detector chip | |
| CN105810607A (en) | Method and system for realizing P-type nitride enhanced HEMT (High Electron Mobility Transistor) through in-situ etching monitoring | |
| CN106449377A (en) | HgCdTe (mercury cadmium telluride) etching mask capable of automatically controlling forming end point and removal method thereof | |
| US8071460B2 (en) | Method for manufacturing semiconductor device | |
| CN206282822U (en) | A kind of mercury cadmium telluride etch mask for automatically controlling shaping terminal | |
| CN116163011A (en) | Preparation method of tellurium-cadmium-mercury epitaxial material Hall test sample | |
| CN108022837B (en) | Etching process for preparing HBT base electrode | |
| CN105321826A (en) | Method of manufacturing semiconductor device and semiconductor device | |
| JPH11135522A (en) | Manufacture of compound semiconductor device | |
| CN102800587A (en) | Process for producing schottky diode | |
| CN104779162B (en) | A kind of method for improving trench VDMOS device gate oxide breakdown voltage | |
| CN106025000A (en) | Handling method for epitaxy defect | |
| CN100367450C (en) | Method for producing blocking-layer | |
| CN104681444B (en) | A kind of method for improving trench VDMOS device gate oxide breakdown voltage | |
| CN109003962A (en) | A kind of manufacturing method of high frequency silicon capacitor | |
| CN218730962U (en) | Semiconductor dielectric layer structure | |
| JPH0645617A (en) | Manufacture of single-crystal thin-film member | |
| JP2005150208A (en) | Evaluation method of soi wafer | |
| CN114141645A (en) | Method for detecting PN junction effective junction depth of mercury cadmium telluride chip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |