The Characteristics of 6-Inch GaN on Si RF HEMT with High Isolation Composited Buffer Layer Design
, Hsien-Chin Chiu 1,*, Chih-Tien Chen 2 and Kuo-Jen Chang 2Round 1
Reviewer 1 Report
Comments for electronics-1026371
The manuscript described the performance improvement of GaN on Si RF power devices using AlGaN blocking layer. The manuscript is interesting and well organized and written. The conclusion is clear. But the resolution of the figures is low. I would recommend this manuscript to be accepted after increasing the figure resolution.
Author Response
Ans: Sorry for the incaution mistakes and we have corrected them in the revised version. Thanks for your careful reading. I have modified several figures in the manuscript and increased the resolution of figure 1, 2, 5, 6, 7.
Reviewer 2 Report
This manuscript demonstrated measurement results, however, due to some logic flaws, it is very difficult for readers to draw solid conclusions. In order to make it beneficial for the community, the flaws needs to be improved.
Major logic flaws include:
1. Based on the sample description in Lines 41 to 43, device A has BB and F-doped/C-doped buffer layer, device B has no BB or F-doped/C-doped buffer layer. However, the performance difference between these two samples can be casued by either the BB, or the F/C buffer doping, or the interaction between BB and buffer doping. To draw valid conclusion about the effect of BB, another sample, which does not have BB but has F/C buffer doping should be studies and compared to the existing samples.
2. Figure 1(c) and Figure 2 discussed the situations of BB. In order to demonstrate the improvement after using BB, the situations without using BB should also be presented. Without a comparison, it is difficult to know whether the situation is changed or not. Specifically, the energy levels of a sample with no BB must be presented to compare with Figure 1(c), and the SIMS result of such a sample should be presented to compare with Figure 2.
3. line 70, "In the Figure 2, the Fe atoms were limited to the AlGaN back barrier because of the lattice constant of AlGaN is lower than that of GaN." The logic here is not clear. The author should explain why small lattice constant leads to larger Fe concentration in more details, or give a reference.
4. MOCVD growth details such as growth temperatures and doping concentrations should be presented. This information is important for other researchers to understand the results and for future comparisons with other work.
There are also minor issues including:
1. There is no definition of Er and Et in Figure 1(c).
2. Figure 3 does not have child-labels (a)(b)(c)(d).
3. In line 60, there should be a space in 'depictedin'.
These issues bring confusion for readers.
In addition, the English of this munuscript must be improved, for example, in Lines 67 to 69, "However, if the excess Fe atoms diffusion into the GaN channel layer behave similarly to defects and thus degrade the device performance. Thus, this study to reduce the Fe atoms diffusion by using an AlGaN back barrier." These sentences contain fatal grammar errors, which may lead to misunderstandings, and should not appear in a Scientific paper.
Author Response
As attached file
Author Response File: 
Author Response.pdf
Reviewer 3 Report
The authors reported about the influence of back barrier layer on AlGaN/GaN HEMT performance. Improvement of static and dynamic HENT properties was observed and discussed. The paper is well written and potentially interesting for HEMT designer community. I recommend it for publishing essentially as is or with one minor, optional recommendation: colors of IdVg(log scale) should by aligned according to colors for linear scale.
Author Response
Ans: Sorry for the incaution mistakes and we have corrected it in the revised version. Thanks for your careful reading. I have modified the colors of Id-Vg(log scale) to aligned according to colors for linear scale.
Round 2
Reviewer 2 Report
The logic flaws have been fixed after the revision.
