AC Photovoltaic Inspection of P-N Junctions having High Leakage Current

1989 ◽  
Vol 163 ◽  
Author(s):  
N. Honma ◽  
H. Shimizu ◽  
C. Munakata ◽  
M. Ogasawara

AbstractA focused photon beam chopped at 2 kHz scans p-n junctions in a p-type Si wafer and ac photovoltages are capacitively measured in order to inspect homogeneities of the junctions. It is found that the ac photovoltages are high not only in the junction areas but also in the field oxide regions around the junctions when the junctions are leaky. This indicates that dense positively charged traps exist at the interface between the heavily boron implanted Si substrate and the field oxide layer around the high leakage junction, and that the traps cause the increase in both the junction leakage current and the ac photovoltage.

2019 ◽  
Vol 9 (11) ◽  
pp. 2373 ◽  
Author(s):  
Chunyan Song ◽  
Xuelin Yang ◽  
Panfeng Ji ◽  
Jun Tang ◽  
Shan Wu ◽  
...  

The role of low-resistivity substrate on vertical leakage current (VLC) of AlGaN/GaN-on-Si epitaxial layers has been investigated. AlGaN/GaN high-electron-mobility transistors (HEMTs) grown on both p-type and n-type Si substrates with low resistivity are applied to analyze the vertical leakage mechanisms. The activation energy (Ea) for p-type case is higher than that for n-type at 0–600 V obtained by temperature-dependent current-voltage measurements. An additional depletion region in the region of 0–400 V forms at the AlN/p-Si interface but not for AlN/n-Si. That depletion region leads to a decrease of electron injection and hence effectively reduces the VLC. While in the region of 400–600 V, the electron injection from p-Si substrate increases quickly compared to n-Si substrate, due to the occurrence of impact ionization in the p-Si substrate depletion region. The comparative results indicate that the doping type of low-resistivity substrate plays a key role for VLC.


2007 ◽  
Vol 556-557 ◽  
pp. 453-456 ◽  
Author(s):  
T. Umeda ◽  
Norio Morishita ◽  
Takeshi Ohshima ◽  
Hisayoshi Itoh ◽  
Junichi Isoya

Carbon antisite-vacancy pair (CSiVC) is a fundamental defect in SiC, and is theoretically predicted to be very stable in p-type materials. However, this pair was found only in the form of a negatively charged state (i.e., the SI5 center = CSiVC −) in n-type and semi-insulating 4H-SiC, and yet, its presence has not been shown in p-type SiC. In this report, we present the first EPR observation on positively charged CSiVC pairs in p-type 4H-SiC. By carefully examining p-type samples after electron irradiation, we found a pair of new defects with C3v and C1h symmetries. They correspond to “c-axial” pairs (C3v) and “basal” pairs (C1h) of CSiVC +, respectively. The positively charged pairs are characterized by a strong 13C hyperfine interaction due to a dangling bond on a carbon antisite (CSi), which is successfully resolved for the c-axial pairs.


2018 ◽  
Vol 6 (5) ◽  
Author(s):  
Frederick Ray Gomez

The technical paper discusses the reduction of high leakage current failures of semiconductor IC (integrated circuit) packages by eliminating the ESD (electrostatic discharge) events during assembly process and ensuring the appropriate machine grounding and ESD controls.  It is imperative to reduce or ideally eliminate the leakage current failures of the device to ensure the product quality, especially as the market becomes more challenging and demanding.  After implementation of the corrective and improvement actions, high leakage current occurrence was reduced from baseline of 5784 ppm to 1567 ppm, better than the six sigma goal of 4715 ppm.


1988 ◽  
Vol 94 (1-6) ◽  
pp. 431-434 ◽  
Author(s):  
Yoshikatsu Nagasawa ◽  
Hideyuki Ishida ◽  
Fusami Soeda ◽  
Akira Ishitani ◽  
Ichiro Yoshii ◽  
...  
Keyword(s):  
Ft Ir ◽  

2020 ◽  
Vol 1014 ◽  
pp. 144-148
Author(s):  
Ling Sang ◽  
Jing Hua Xia ◽  
Liang Tian ◽  
Fei Yang ◽  
Rui Jin ◽  
...  

The effect of the field oxidation process on the electrical characteristics of 6500V 4H-SiC JBS diodes is studied. The oxide thickness and field plate length have an effect on the reverse breakdown voltage of the SiC JBS diode. According the simulation results, we choose the optimal thickness of the oxide layer and field plate length of the SiC JBS diode. Two different field oxide deposition processes, which are plasma enhanced chemical vapor deposition (PECVD) and low pressure chemical vapor deposition (LPCVD), are compared in our paper. When the reverse voltage is 6600V, the reverse leakage current of SiC JBS diodes with the field oxide layer obtained by LPCVD process is 0.7 μA, which is 60% lower than that of PECVD process. When the forward current is 25 A, the forward voltage of SiC JBS diodes with the field oxide layer obtained by LPCVD process is 3.75 V, which is 10% higher than that of PECVD process. There should be a trade-off between the forward and reverse characteristics in the actual high power and high temperature applications.


Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 508 ◽  
Author(s):  
Stanislav Tiagulskyi ◽  
Roman Yatskiv ◽  
Hana Faitová ◽  
Šárka Kučerová ◽  
David Roesel ◽  
...  

We study the effect of thermal annealing on the electrical properties of the nanoscale p-n heterojunctions based on single n-type ZnO nanorods on p-type GaN substrates. The ZnO nanorods are prepared by chemical bath deposition on both plain GaN substrates and on the substrates locally patterned by focused ion beam lithography. Electrical properties of single nanorod heterojunctions are measured with a nanoprobe in the vacuum chamber of a scanning electron microscope. The focused ion beam lithography provides a uniform nucleation of ZnO, which results in a uniform growth of ZnO nanorods. The specific configuration of the interface between the ZnO nanorods and GaN substrate created by the focused ion beam suppresses the surface leakage current and improves the current-voltage characteristics. Further improvement of the electrical characteristics is achieved by annealing of the structures in nitrogen, which limits the defect-mediated leakage current and increases the carrier injection efficiency.


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