CN102856188A - Wet etching method for gallium nitride-based device - Google Patents

Wet etching method for gallium nitride-based device Download PDF

Info

Publication number
CN102856188A
CN102856188A CN2012102779073A CN201210277907A CN102856188A CN 102856188 A CN102856188 A CN 102856188A CN 2012102779073 A CN2012102779073 A CN 2012102779073A CN 201210277907 A CN201210277907 A CN 201210277907A CN 102856188 A CN102856188 A CN 102856188A
Authority
CN
China
Prior art keywords
gallium
nitride
based devices
wet etching
etching method
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.)
Pending
Application number
CN2012102779073A
Other languages
Chinese (zh)
Inventor
蔡金宝
王金延
刘洋
徐哲
王茂俊
于民
解冰
吴文刚
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Peking University
Original Assignee
Peking University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Peking University filed Critical Peking University
Priority to CN2012102779073A priority Critical patent/CN102856188A/en
Publication of CN102856188A publication Critical patent/CN102856188A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Weting (AREA)
  • Led Devices (AREA)

Abstract

The invention provides a wet etching method for a gallium nitride-based device. The method includes depositing a protective layer on the surface of the gallium nitride-based device; coating photoresist on the protective layer and photoetching a to-be-etched area; etching the protective layer of the to-be-etched area; removing residual photoresist; subjecting the gallium nitride-based device to an oxidation treatment under a high temperature condition; and placing the gallium nitride-based device after the oxidation treatment into a corrosive solution for the etching. According to the method, an etch trench with a flat bottom and smooth step edges can be produced, damage to the device can be reduced effectively, and the method is suitable for the isolation technique and other etching processes of the gallium nitride-based device.

Description

A kind of wet etching method of gallium-nitride-based devices
Technical field
The invention belongs to microelectronics technology, relate to the lithographic technique of semiconductor device, be specifically related to a kind of wet etching method of gallium-nitride-based devices.
Background technology
Device take AlGaN/GaN as material foundation is referred to as gallium-nitride-based devices, AlGaN/GaN hetero junction field effect pipe (heterostructure field effect transistors for example, HFET), heterojunction bipolar transistor (heterostructure bipolar transistor, HBT) etc.Gallium-nitride-based devices has the advantages such as working temperature height, breakdown field is powerful, cut-off frequency is high, power density is large, is the first-selection in the high-power field of future microwave, more becomes the nearly during the last ten years research emphasis in microwave power device field.
Be different from the traditional Si device system, the chemistry of GaN sill and physical property are all highly stable, to such an extent as to current its etching technics mainly is take ion etching as main dry etch process, but this technique can be given GaN base device injury inevitably, and device performance is descended.
Summary of the invention
The object of the present invention is to provide a kind of wet etching method of gallium-nitride-based devices, can make the etching tank that bottom land is smooth, step edge is smooth, and can effectively reduce the damage that device is caused.
For achieving the above object, the present invention adopts following technical scheme:
A kind of wet etching method of gallium-nitride-based devices, its step comprises:
1) at gallium-nitride-based devices surface deposition protective layer:
2) apply photoresist at described protective layer, and the photoetching corrosion figure;
3) etching is treated the protective layer of corrosion area;
4) remove the residue photoresist;
5) gallium-nitride-based devices is carried out oxidation processes under hot conditions;
6) place corrosive solution to corrode the gallium-nitride-based devices after the oxidation processes.
Further, described gallium-nitride-based devices comprises that AlGaN/GaN heterojunction device, LED device etc. are based on the semiconductor device of gallium nitride material characteristic.
Further, described protective layer can adopt SiO 2Or the material such as SiN.
Further, the method for described etching includes but not limited to: 1) RIE(reactive ion etching, Reactive Ion Etching) process; 2) BOE(Buffer Oxide Etch, the buffering etching solution) the solution immersion treatment.
Further, the method for described deposit includes but not limited to: PECVD(Plasma Enhanced Chemical Vapor Deposition, plasma enhanced chemical vapor deposition), low-pressure chemical vapor deposition, optical thin film deposition; The preferred PECVD method that adopts.
Further, described photoresist can adopt the materials such as AZ5214; The modes such as contact photolithography are adopted in described photoetching.
Further, carry out described oxidation processes by oxidation furnace, Temperature Setting is 600-900 ℃, and the time is 30min-10h.Can according to the groove depth that will corrode and application, make corresponding modification to the temperature and time of oxidation processes.
Further, described corrosive solution can be alkaline solution, can be acid solution also, includes but not limited to:
A) potassium hydroxide solution or sodium hydroxide solution: its mass concentration is 15%-25%, and its temperature is 50 ℃-100 ℃, and etching time is 5-60 minute;
B) strong acid class solution, such as rare nitric acid, watery hydrochloric acid, hydrofluoric acid and dilute sulfuric acid etc.: its mass concentration is the laboratory typical concentrations, and its temperature is 50 ℃-100 ℃, and etching time is 5-60 minute.
The wet etching method of gallium-nitride-based devices of the present invention for gallium nitride-based material, can obtain the deep trouth greater than 150nm, and its bottom land is smooth, and step edge is smooth, can effectively avoid the damage that causes to device as main dry etch process take ion etching.The inventive method can be applied to the isolation technology of gallium-nitride-based devices, also can be applicable to other etching process of gallium nitride-based material, such as corrosion of enhancement device grid groove etc.
Description of drawings
Fig. 1 is the flow chart of steps of the wet etching method of gallium-nitride-based devices of the present invention.
Fig. 2 is the atomic force microscope images of the isolation channel shoulder height of the embodiment of the invention.
Fig. 3 is the atomic force microscope images of the isolation channel bottom land pattern of the embodiment of the invention.
Fig. 4 is the atomic force microscope images of the isolation channel three-dimensional structure of the embodiment of the invention.
Embodiment
Below by specific embodiment and cooperate accompanying drawing, the present invention is described in detail.
The present invention to the principle that gallium-nitride-based devices carries out wet etching is: at first carry out oxidation processes under hot conditions; Then be soaked in the alkaline solution of constant temperature and corrode.The GaN material at high temperature (is generally more than 600 ℃), can be oxidized, form the oxide of Ga, and the N element is then with N 2Form leave.And the oxide of Ga is amphoteric oxide, can be dissolved in highly basic or strong acid solution at a certain temperature, thereby stays the etching tank structure.
Fig. 1 is the flow chart of steps of wet etching method of the gallium-nitride-based devices of present embodiment.The below is specifically described the method take the isolation technology of AlGaN/GaN HMET as example.The preparation process of this isolation channel comprises:
1) adopt the PECVD method to prepare the SiO that thickness is 500nm on GaN base device surface 2Protective layer.
This step prepares SiO 2The purpose of layer is the non-isolation channel of protection zone, i.e. device area not oxidized and damage under the high-temperature oxygen environment.
2) at described SiO 2Coating photoresist on the layer, and photoetching corrosion figure.
The domain that present embodiment adopts is the isolation structure domain, and the photoresist of employing is AZ5214; Adopt the contact photolithography method to carry out photoetching.
3) etching is treated the SiO of corrosion area 2Protective layer.
The purpose of this step is to etch away the SiO that treats corrosion area 2Protective layer exposes out the isolation channel zone, is convenient to follow-up oxidation, but not the SiO of corrosion area 2Protective layer can not be etched away because the protection of photoresist is arranged.This step employing RIE(reactive ion etching) method is carried out etching.
4) remove the residue photoresist.Adopt the method for organic washing to remove photoresist, solvent is acetone and other organic solvent.
5) step 4) gained gallium-nitride-based devices is put in the oxidation furnace under the purity oxygen environment and carries out oxidation processes.
The purpose in front four steps is before the print oxidation, will not need the zone SiO of oxidation 2Protective layer protects, and needs the zone of oxidation exposed out, carries out oxidation in this step.The Temperature Setting of oxidation is 900 ℃, and the time is 9 hours.
6) gallium-nitride-based devices after the oxidation processes is soaked in potassium hydroxide solution and corrodes, namely make isolation channel after the taking-up.
In this step, the temperature constant of potassium hydroxide solution is 70 ℃; Wherein the ratio of saturated potassium hydroxide solution and water is 1:4, and being converted into mass concentration is 19.7%; Etching time is 30 minutes.
Fig. 2,3 and 4 is for adopting atomic force microscope (AFM) that above-described embodiment gained isolation channel is detected the image of gained, and wherein: Fig. 2 is for being the shoulder height image of isolation channel; The bottom land feature image of Fig. 3 isolation channel; Fig. 4 is the three-dimensional structure image of isolation channel.Can find out, the isolation channel (isolation channel) of this wet etching method preparation, its shoulder height is about 150nm, shown in Fig. 2 upper right corner; Its trench bottom is smooth, and average roughness Ra is 10.7nm; And step edge is neatly smooth.
In above-described embodiment, described gallium-nitride-based devices can be that AlGaN/GaN heterojunction device, LED device etc. are based on the semiconductor device of gallium nitride material characteristic.
In above-described embodiment, described protective layer is except adopting SiO 2Can also adopt the materials such as SiN outward.
In above-described embodiment, step 3) can also adopt BOE(Buffer Oxide Etch except adopting the RIE method to carry out the etching, the buffering etching solution) etc. solution carry out immersion treatment, finish etching.
In above-described embodiment, described deposit can also be adopted the methods such as low-pressure chemical vapor deposition, optical thin film deposition except adopting the PECVD method.
In above-described embodiment, when carrying out oxidation processes by oxidation furnace, temperature can be adjusted in 600-900 ℃ of scope, and the time is 30min-10h.Can according to the groove depth that will corrode and application, make corresponding modification to the temperature and time of oxidation processes.
In above-described embodiment, step 6) can adopt alkaline solution to corrode, and can be acid solution also, includes but not limited to:
A) potassium hydroxide solution or sodium hydroxide solution: its mass concentration is 15%-25%, and its temperature is 50 ℃-100 ℃, and etching time is 5-60 minute;
B) strong acid class solution, such as rare nitric acid, watery hydrochloric acid, hydrofluoric acid and dilute sulfuric acid etc.: its mass concentration is the laboratory typical concentrations, and its temperature is 50 ℃-100 ℃, and etching time is 5-60 minute.
Above embodiment is only in order to technical scheme of the present invention to be described but not limit it; those of ordinary skill in the art can make amendment or is equal to replacement technical scheme of the present invention; and not breaking away from the spirit and scope of the present invention, protection scope of the present invention should be as the criterion so that claim is described.

Claims (10)

1. the wet etching method of a gallium-nitride-based devices, its step comprises:
1) at gallium-nitride-based devices surface deposition protective layer:
2) apply photoresist at described protective layer, and the photoetching corrosion figure;
3) etching is treated the protective layer of corrosion area;
4) remove the residue photoresist;
5) gallium-nitride-based devices is carried out oxidation processes under hot conditions;
6) place corrosive solution to corrode the gallium-nitride-based devices after the oxidation processes.
2. the wet etching method of gallium-nitride-based devices as claimed in claim 1 is characterized in that, described gallium-nitride-based devices comprises the AlGaN/GaN heterojunction device, based on the LED device of gallium nitride material characteristic.
3. the wet etching method of gallium-nitride-based devices as claimed in claim 1 is characterized in that, the method for described deposit comprises: plasma enhanced chemical vapor deposition, low-pressure chemical vapor deposition, optical thin film deposition.
4. the wet etching method of gallium-nitride-based devices as claimed in claim 1 is characterized in that, described protective layer is SiO 2Or SiN.
5. the wet etching method of gallium-nitride-based devices as claimed in claim 1 is characterized in that, adopts RIE method or BOE solution immersion treatment method to carry out described etching.
6. the wet etching method of gallium-nitride-based devices as claimed in claim 1 is characterized in that, carries out described oxidation processes by oxidation furnace.
7. the wet etching method of gallium-nitride-based devices as claimed in claim 6 is characterized in that, the temperature of carrying out described oxidation processes is 600-900 ℃, and the time is 30min-10h.
8. the wet etching method of gallium-nitride-based devices as claimed in claim 1 is characterized in that, described corrosive solution is alkaline solution or acid solution.
9. the wet etching method of gallium-nitride-based devices as claimed in claim 8, it is characterized in that: described corrosive solution is potassium hydroxide solution or sodium hydroxide solution, and its mass concentration is 15%-25%, and temperature is 50 ℃-100 ℃, and etching time is 5-60 minute.
10. the wet etching method of gallium-nitride-based devices as claimed in claim 8 is characterized in that, described corrosive solution is a kind of in the following acid solution: rare nitric acid, watery hydrochloric acid, hydrofluoric acid, dilute sulfuric acid.
CN2012102779073A 2012-08-06 2012-08-06 Wet etching method for gallium nitride-based device Pending CN102856188A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2012102779073A CN102856188A (en) 2012-08-06 2012-08-06 Wet etching method for gallium nitride-based device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2012102779073A CN102856188A (en) 2012-08-06 2012-08-06 Wet etching method for gallium nitride-based device

Publications (1)

Publication Number Publication Date
CN102856188A true CN102856188A (en) 2013-01-02

Family

ID=47402661

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2012102779073A Pending CN102856188A (en) 2012-08-06 2012-08-06 Wet etching method for gallium nitride-based device

Country Status (1)

Country Link
CN (1) CN102856188A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103258739A (en) * 2013-05-13 2013-08-21 北京大学 Grooved-gate gallium-nitride-based enhancement device preparation method based on self-stopped etch
CN104282548A (en) * 2014-09-12 2015-01-14 电子科技大学 Etching method for III-V-group compound semiconductor materials
CN106257624A (en) * 2016-08-29 2016-12-28 北京代尔夫特电子科技有限公司 A kind of caustic solution of compound semiconductor
CN106444293A (en) * 2016-09-27 2017-02-22 易美芯光(北京)科技有限公司 Preparation method of metal pattern
WO2017101535A1 (en) * 2015-12-18 2017-06-22 北京代尔夫特电子科技有限公司 Wet corrosion method of group iii nitride
CN107045975A (en) * 2016-02-05 2017-08-15 北京大学 The preparation method for Ohmic contact of being slotted based on the gallium nitride-based material that self-stopping technology is etched

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101625971A (en) * 2008-07-09 2010-01-13 中国科学院半导体研究所 Method for etching class-III nitride by using photo-assisted oxidation wet method
CN102171830A (en) * 2008-07-31 2011-08-31 克里公司 Normally-off semiconductor devices and methods of fabricating the same
CN102386213A (en) * 2010-09-02 2012-03-21 富士通株式会社 Semiconductor device, method of manufacturing the same, and power supply apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101625971A (en) * 2008-07-09 2010-01-13 中国科学院半导体研究所 Method for etching class-III nitride by using photo-assisted oxidation wet method
CN102171830A (en) * 2008-07-31 2011-08-31 克里公司 Normally-off semiconductor devices and methods of fabricating the same
CN102386213A (en) * 2010-09-02 2012-03-21 富士通株式会社 Semiconductor device, method of manufacturing the same, and power supply apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
F.ROCCAFORTE等: "Electrical behavior of AlGaN/GaN heterostuctures upon high-temperature selective oxidation", 《JOURNAL OF APPLIED PHYSICS》, vol. 106, 20 July 2009 (2009-07-20), XP012123573, DOI: doi:10.1063/1.3174438 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103258739A (en) * 2013-05-13 2013-08-21 北京大学 Grooved-gate gallium-nitride-based enhancement device preparation method based on self-stopped etch
CN103258739B (en) * 2013-05-13 2016-12-28 北京大学 The preparation method of notched gates nitridation gallio enhancement device based on self-stopping technology etching
CN104282548A (en) * 2014-09-12 2015-01-14 电子科技大学 Etching method for III-V-group compound semiconductor materials
WO2017101535A1 (en) * 2015-12-18 2017-06-22 北京代尔夫特电子科技有限公司 Wet corrosion method of group iii nitride
CN107045975A (en) * 2016-02-05 2017-08-15 北京大学 The preparation method for Ohmic contact of being slotted based on the gallium nitride-based material that self-stopping technology is etched
CN106257624A (en) * 2016-08-29 2016-12-28 北京代尔夫特电子科技有限公司 A kind of caustic solution of compound semiconductor
CN106444293A (en) * 2016-09-27 2017-02-22 易美芯光(北京)科技有限公司 Preparation method of metal pattern

Similar Documents

Publication Publication Date Title
CN102856188A (en) Wet etching method for gallium nitride-based device
CN107210323A (en) normally-off III-nitride transistor
CN101459080B (en) Method for manufacturing gallium nitride-based field effect transistor
CN104282548A (en) Etching method for III-V-group compound semiconductor materials
CN109148368B (en) Epitaxial layer transfer method of AlGaN/GaN HEMT device
JPWO2007105281A1 (en) Method for manufacturing compound semiconductor device and etching solution
CN103077891B (en) Super-junction-based gallium nitride HEMT (High Electron Mobility Transistor) device and preparation method thereof
CN109244026B (en) Transfer method of epitaxial layer of semiconductor device
WO2017101535A1 (en) Wet corrosion method of group iii nitride
CN104037218B (en) A kind of high-performance AlGaN/GaN HEMT high-voltage device structure based on polarity effect and manufacture method
CN109411350A (en) A kind of preparation method of GaN base p-type grid structure
CN104269469A (en) Method for reducing ohmic contact resistance of wide bandgap semiconductor
CN106298904A (en) Nitridation gallio enhancement device with gallium nitride interposed layer and preparation method thereof
CN103268857B (en) A kind of self-stopping technology lithographic method based on gallium nitride-based material
CN106486355B (en) A kind of wet etching method of InGaP
CN104465403A (en) Enhanced AlGaN/GaN HEMT device preparation method
CN103258739B (en) The preparation method of notched gates nitridation gallio enhancement device based on self-stopping technology etching
CN106548939B (en) The system and method for the enhanced HEMT device of recessed grid is realized by light auxiliary etch self-stopping technology
CN107045975A (en) The preparation method for Ohmic contact of being slotted based on the gallium nitride-based material that self-stopping technology is etched
CN104037217B (en) AlGaN/GaN HEMT switching element structure based on composite dipole layer and manufacturing method
CN110911484B (en) Enhanced GaN HEMT device prepared by wet etching assisted doping and preparation method
CN112542384B (en) Manufacturing method of gallium nitride enhanced device
CN102820322B (en) GaN-based enhancement device containing ferroelectric layer and preparation method
CN109411351B (en) Groove preparation method of GaN-based material
CN101673670B (en) Method for reducing warpage of III-nitride self-supporting wafer

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C12 Rejection of a patent application after its publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20130102