研究目的
To develop a technique for selective deposition of polycrystalline diamond on AlGaN/GaN HEMT structures using HFCVD without damaging the underlying layers, for thermal management in high-power electronic devices.
研究成果
The developed technique successfully enables selective HFCVD diamond deposition on AlGaN/GaN wafers with excellent selectivity and minimal damage to the underlying layers, as confirmed by multiple characterization methods. This approach is scalable for large-scale production and beneficial for thermal management in high-power GaN devices, though further optimization is required to address thermal stress and interface resistance.
研究不足
The process requires a protective SiNx layer, which adds thermal resistance and interfaces, potentially limiting thermal performance. The diamond growth temperature of 720-750°C may induce thermal stress, affecting electrical properties. The technique is specific to HFCVD and may not be directly applicable to other CVD methods. Optimization of SiNx thickness for thermal properties is needed.
1：Experimental Design and Method Selection:
The study uses a selective area deposition approach with HFCVD for diamond growth, incorporating a PECVD SiNx protective layer to prevent damage to the AlGaN/GaN layers. The method involves photolithographic patterning with nano-diamond seeds dispersed in photoresist, followed by RIE etching and HFCVD growth with optimized methane concentration.
2：Sample Selection and Data Sources:
AlGaN/GaN HEMT structures grown on 100 mm Si (111) wafers via MOCVD are used as the starting material. Characterization data include SEM, AFM, Raman spectroscopy, HRXRD, RSM, and electrical measurements.
3：List of Experimental Equipment and Materials:
Equipment includes MOCVD reactor for wafer growth, PECVD reactor (MPS-150, AGS Plasma System, Inc) for SiNx deposition, optical lithography tools, RIE chamber, HFCVD chamber (Crystallume, Inc.), pyrometer (Omega OS4000), thermocouple (type-K), SEM (FEI Helios 400), AFM (Bruker Dimension ICON), TEM (JEOL 1200EXII), Raman system (Horiba LabRAM), HRXRD system (Rigaku SmartLab), C-V system (Materials Development Corp.), and mobility measurement system (LEI 1605B). Materials include AlGaN/GaN wafers, SiNx, nano-diamond seeds, photoresist, methane, hydrogen, and other CVD gases.
4：Experimental Procedures and Operational Workflow:
The process involves depositing a PECVD SiNx layer on the wafer, patterning with photolithography and nano-diamond seeding, RIE etching to remove excess seeds and thin SiNx, and HFCVD diamond growth at 720-750°C with 3% methane for 2 hours. Characterization is performed before and after deposition.
5：Data Analysis Methods:
Data are analyzed using software tools for SEM, AFM, Raman spectroscopy (peak fitting), HRXRD (lattice constant determination), RSM (strain analysis), and electrical measurements (carrier concentration and mobility calculation).
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容-
SEM
Helios 400
FEI
Used for morphology and thickness characterization of diamond films and cross-section imaging.
-
AFM
Dimension ICON
Bruker
Used for surface morphology analysis.
-
TEM
1200EXII
JEOL
Used for cross-section imaging of the AlGaN/GaN structure.
-
HRXRD system
SmartLab
Rigaku
Used for high-resolution x-ray diffraction and reciprocal space mapping.
-
MOCVD reactor
Used for growing AlGaN/GaN HEMT structures on silicon wafers.
-
PECVD reactor
MPS-150
AGS Plasma System, Inc
Used for depositing SiNx protective layer on the wafers.
-
HFCVD chamber
Crystallume, Inc.
Used for diamond deposition via hot filament chemical vapor deposition.
-
Pyrometer
OS4000
Omega
Used for temperature measurement during diamond deposition.
-
Thermocouple
Type-K
Used for temperature measurement during diamond deposition.
-
Raman system
LabRAM
Horiba
Used for Raman spectroscopy to analyze material properties.
-
C-V system
Materials Development Corp.
Used for capacitance-voltage measurements for electrical characterization.
-
Mobility measurement system
LEI 1605B
Lehighton Electronics Inc.
Used for contactless mobility measurements.
-
登录查看剩余10件设备及参数对照表
查看全部
