High−Performance 4H−SiC UV p−i−n Photodiode: Numerical Simulations and Experimental Results
Round 1
Reviewer 1 Report
This paper reports the research into SiC photodiode with efforts in simulative and experimental investigation. It is an important and interesting topic to study. The content of the paper is well organized and the results are clearly presented. I have some minor questions that the author could consider addressing.
Title. I would prefer using ":" than "."
Abstract. Usually, the abstract is a single paragraph.
I am a little confused about the structure of the p-i-n junction, it seems the "intrinsic" region is the n-type epitaxial layer of 16.5 um thick?
I notice a peak for the photocurrent, but I am confused about the underlying physics. Why the photoresponse for a shorter wavelength decreases so dramatically?
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this work, Rao et. al. reported a numerical method to simulate the SiC p-i-n photodiode properties. The results from the simulation was compared to the experimental electrical and optical measurements and they claimed a good agreement found between simulation and experiments. The authors also reported in this work that the photo-response peak of the photodiode is R=0.204 A/W at -30V, which is the best value compared literature. This work show interesting results and has potential to make impact in the growing SiC field. However, I would recommend some suggestions before this paper is publishable. The results are fine in this work, but the writing or organization of this manuscript needs more work.
It would benefit the paper if the authors have an Experimental section in the main text. This would include the details of the fabrication of the p-i-n junction, the kind of lithography/implantation used, any annealing used. It would also be better if the authors can note the thickness of each layers in Figure 1, for both experiments and simulation.
Is there any reason why n-type region is denoted as n+? In table 1, what do the authors mean by n+ and n-?
Page 7, “an UV radiation from a remotely-controlled monochromator was used to measure the J-V characteristics at different wavelengths”. This sentence needs rewriting. It’s very confusing. “An UV radiation was used to measure the J-V” is not physically correct.
External Quantum Efficiency is usually donated as “EQE”
A/W should be defined in the text.
As to Figure 5 and table 4, this is nice result. But the authors still should elaborate how these experiments were performed. How was the voltage applied to the p-i-n junction, longitudinal or transverse? There is no description about this critical experiment, but only mentioned a reference (3). Once again, I would strongly recommend the authors to add this to the experimental section or even have a schematic to how this is measured.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
-what do you mean by TRAINED in "The finite-element methods for the semiconductor device simulation have been trained with additional EO properties achieved from experimental studies on the same materials and device15". Do you refer to AI, system expert?
-Does you simulation tool allow to introduce a third dimension (for example to introduce anode fingers in fig. 1)?
-In table 1 thickness refers to Fig1. Maybe you mean Fig.2 which is a profile?
-When you say: "have been tuned by comparison with these experimental results" you mean that initial values of parameters have been changed to adjust better measurements? Could you indicate initial and final values od parameters or % of variation in parameters to address the magnitude of changes and if those changes are reasonable or compatible with tolerances in ellipsometric analysis, for example?
-Could you provide information and photos of the method to measure and establish quantum efficiency?
-In Fig. 3 profiles are simulated?
-Is it possible to establish comparisons of the proposed with other UV detectors?
-Some technology details, a sort description of the process and some photos of the chips would be quite illustrative.
-Possibility to integrate with transimpedance amplifiers?
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
The authors present in this article the numerical simulation and experimental results for a high-performance p-i-n diode. The article is very well written, and the experimental results validate the numerical simulation respectively the simulation strategy. It is worth noting the tutorial style of this very useful article for those who want to simulate, design such semiconductor devices. All the theoretical aspects or notions used in the article are well known in the specialized literature. The contribution is rather didactic in nature and I consider it from this perspective very useful and well organized. Unfortunately, the template for Electronics journal is not followed, nor is it the standard form for references. This situation must be remedied by the authors.
This paper contains some interesting points that are valuable for readers working in this field but besides the experimental results it is recommended to present the experimental setup to allow those interested in reproducing the results a support from an experiential perspective.
Also, the authors did not present enough literature in relation to the abundance in this area, the motivation for this research is summary. The authors failed to write the objectives and especially the novelty elements of this work in relation to the existing literature. All this bothers me that at this point I recommend a major revision primarily for reasons related to the lack of presentation, the description of the experimental setup.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 4 Report
The revised version of the paper "High-performance 4H-SiC UV p-i-n photodiode: numerical 2 simulations and experimental results" corrects the observations and recommendations previously invoked. The new version meets the conditions for publication in this form.
