4H-SiC LGAD Epiwafer *S
In recent years, silicon-based rapid timing detectors have been widely used in fields such as high-energy physics, nuclear physics, and space exploration. However, Si detectors often require complex low-temperature systems to operate in irradiation environments, and their detection performance decreases with increasing irradiation dose. Compared to silicon, silicon carbide (SiC) has a wider bandgap, higher atomic displacement energy, saturated electron drift velocity, and thermal conductivity. Meanwhile, low gain avalanche detectors (LGADs), due to their moderate gain, avoid crosstalk and high noise caused by high multiplication, and can maintain high detector signals without increasing noise. Therefore, 4H-SiC particle detectors, especially LGADs, are highly suitable for detecting minimum ionizing particle (MIPs) under extreme radiation and high temperatures. PAM-XIAMEN can grow customized 4H-SiC LGAD epitaxial wafers, and the specific structure is as follows for reference only:
1. Epitaxial Structure of 4H-SiC LGAD
| Epi Layer | Thickness | Doping Concentration |
| p++ contact layer | – | – |
| n+ gain layer | 0.5 µm | – |
| n- drift layer | – | 2×1014 cm–3 |
| n+ buffer layer | – | – |
| n++ type 4H-SiC substrate |
2. Research on 4H–SiC Low Gain Avalanche Detector
In terms of device design and performance characterization, researchers have found significant advantages in using this structure to prepare devices compared to traditional 4H-SiC PiN diodes. It has achieved high breakdown voltage and low leakage current in I-V characteristic testing, and the C-V characteristics further verify the optimization of the device’s electric field distribution. In addition, the alpha particle irradiation experiment revealed a unique phenomenon of low gain (2-3 times) charge carrier multiplication, and it is speculated that insufficient doping concentration in the gain layer or space charge effects may be limiting factors.
In terms of process optimization and charge collection mechanism, researchers used RASER software to model and analyze the correlation between metal electrode thickness and annealing temperature on device leakage current, and successfully suppressed leakage current by four orders of magnitude through process parameter control. Experimental data shows that the optimized device achieves a charge collection efficiency of 90% under a bias voltage of 100V, and the gain factor is doubled at 150V, confirming the critical role of manufacturing processes in improving performance.
In summary, 4H-SiC LGAD provides a new solution for high-energy particle detection due to its high voltage resistance, low noise, and controllable gain characteristics. Although limited by gain levels, doping engineering and structural optimization have the potential to break through performance bottlenecks and have important applications in future particle physics experiments and radiation detection fields.
Whether you need 4H-SiC wafers for research or for industrial applications, please contact us email at [email protected] and [email protected].