Review Reports - Mitigating WL-to-WL Disturbance in Dynamic Random-Access Memory (DRAM) through Adopted Spherical Shallow Trench Isolation with Silicon Nitride Layer in the Buried Channel Array Transistor (BCAT)

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper proposes a mitigation technique for the Pass Gate Effect (PGE) on DRAM, based on spherical Shallow Trench Isolations (STI) and on the introduction of a Si3N layer within the STI itself. Presented results are only based on simulations.

The paper is quite clear in the language, less clear in the description of the methodology description and results presentation. Also the conclusions should be better connected to the results presented and discussed.

Here some comments:

- Abstract, line 25: authors cite a 82.4% reduction in PGE but I cannot find in the rest of the paper such a number. The only number which is connected with the PGE reduction is at page 7, but the reported number there is 9.13%. Please clarify

- 1. Introduction, line 53: do authors mean "The ongoing size reduction in DRAM"?

- 1. Introduction, line 63: are the one presented experimental data or simulation data?

- 2. Simulation Methodology: which is the relationship between Fig. 1(b) and Fig. 2?

- 2. Simulation Methology, line 91: "used to the BCAT structure"-->"used in the BCAT structure" ? Please check

- 2. Simulation Methology, line 93-94: please check the sentence

- 2. Simulation Methology. Lines 95-97 and lines 98-100 are basically expressing the same concept. I would cancel the repetion and keep only one of the two

-3. PGE Phenomenon and Investigation. Please, check Vth through the paragraph and correct the subscript where necessary (for instance line 115, 116, 117 twice etc etc). Same for the current value chosen for Vth extraction: lines 129 and 132 (10-7, correct the superscript and please add the measure unit)

- 3. PGE Phenomenon and Investigation. page 5 is very foggy to me and should be made more clear and readable. For instance, I would suggest to clearly explain what (line 148) Tox, Csi and Cox are, with respect to Fig. 2. Then it is not clear to me how Fig 4 and Fig 5 are derived: they both plot the same quantities (PGE vs Dielectric constant), but the difference is cricptical. Authors declare (line 152) that Fig 5 are experimental data, which are validated in the comparison with Fig 4. Please, clarify

- 4. Proposal Structure and Simulation Results: check subscripts (lines 215, 234, 287, 288, and others )

- 4. Proposal Structure and Simulation Results, line 167: "earlier": where?

- 4. Proposal Structure and Simulation Results, line 282: what is the "old" STI?

- 5. Conclusions, line 321: how "four orders of magnitude" have been estimated as a reduction of PGE? This is not clear from the paper and this numer has not been discussed in the previous part of the work

- Is the spherical STI technologically possible from the point of view of the litography process?

Comments on the Quality of English Language

The overall quality of English Language is good even if not uniform through the paper. Some Sections (Introduction) are well written and clear; the others need some minor revision.

Author Response

Original Article Title: “Mitigating WL-to-WL disturbance in DRAM through adopted Spherical Shallow Trench Isolation with silicon nitride layer at the BCAT”

To: Editor

Re: Response to reviewers

Dear Editor,

Thank you for giving us the opportunity to strengthen our manuscript with your valuable comments and queries. It's a great honor to have your review. Our paper has been added a detailed explanations to reflect the review you presented. We deeply appreciate again the times and efforts the reviewer generously shared for reviewing our manuscript. We look forward to publishing your paper as soon as possible.

Best regards,

Yeon Seok Kim et al.

Reviewer: 1

Abstract, line 25: authors cite a 82.4% reduction in PGE but I cannot find in the rest of the paper such a number. The only number which is connected with the PGE reduction is at page 7, but the reported number there is 9.13%. Please clarify.

Author response: Thank you for your deep and kind comments.

Author action: We revised to feedback actively your opinions at abstract section. We added a Fig. 10 summarizing the study results to clearly state that 82.4% PGE was reduced.

Introduction, line 53: do authors mean "The ongoing size reduction in DRAM"?

Author response: Yes, you are correct. Thank you for your deep and knowledgeable comments. We expressed the continuous DRAM size reduction in confusion.

Author action: We rewrite the word "components" as "cells."

Introduction, line 63: are the one presented experimental data or simulation data?

Author response: Thank you for reviewing our manuscript and your detailed comments. The data represented in line 63 are simulation data.

Author action: We rewritten it from experimental data to simulation data so as not to be confused.

Simulation Methodology: which is the relationship between Fig. 1(b) and Fig. 2?

Author response: Thank you for your kind and deep-knowledgeable comments. Fig. 2 is the 2D representation of the structure of the red dash box area in Fig. 1(b). The reason why Fig. 2 is needed is to express various dimensions on the figure.

If various dimensions were expressed in Fig. 1(b), the picture would have become complicated and difficult to recognize.

Simulation Methodology, line 91: "used to the BCAT structure"-->"used in the BCAT structure”? Please check.

Author response: Thank you for your kind and detailed comments.

Author action: We revised to feedback your suggestion about phrase. We replaced the word "to" as "in."

2. Simulation Methodology, line 93-94: please check the sentence.

Author response: Thank you for reviewing our manuscript and your valuable comments. The sentence in line 93-94 was not clear what we were trying to convey.

Author action: We revised to feedback your suggestion at sentence. We rewritten the sentence to clarify the meaning.

Simulation Methodology. Lines 95-97 and lines 98-100 are basically expressing the same concept. I would cancel the reception and keep only one of the two.

Author response: Thank you for your kind and polite comments.

Author action: We revised to feedback your opinion at Simulation Methodology section. We deleted one of the two sentences with overlapping meanings.

PGE Phenomenon and Investigation. Please, check Vth through the paragraph and correct the subscript where necessary (for instance line 115, 116, 117 twice etc etc). Same for the current value chosen for Vth extraction: lines 129 and 132 (10-7, correct the superscript and please add the measure unit)

Author response: Thank you for reviewing our manuscript and your detailed comments. We missed the details of how to write V_th and PGE extraction current.

Author action: We revised to feedback your opinion at subscript and superscript. We changed the subscript and superscript of V_th and current correctly. In addition, we also changed the Optimization for Physical STI section and the Conclusion section of V_th's subscript.

PGE Phenomenon and Investigation. page 5 is very foggy to me and should be made more clear and readable. For instance, I would suggest to clearly explain what (line 148) Tox, Csi and Cox are, with respect to Fig. 2. Then it is not clear to me how Fig 4 and Fig 5 are derived: they both plot the same quantities (PGE vs Dielectric constant), but the difference is cryptical. Authors declare (line 152) that Fig 5 are experimental data, which are validated in the comparison with Fig 4. Please, clarify.

Author response: Thank you for reviewing our manuscript and your valuable comments. We measured PGE by changing the dielectric material in STI by simulation. (Fig.4) By changing between AWL and FPWL into a capacitor, DRAM devices can be interpreted from a circuit perspective. So, we constructed an equivalent circuit and obtained the ideal capacitance through a mathematical equation. (Fig.5) As a result, the tendencies of Fig. 4 and Fig. 5 match, so the simulation results could be verified. Lastly, T_ox, C_si, and C_ox are named after capacitors that exist between AWL and FPWL.

Author action: We additionally wrote down the description that DRAM devices are interpretable from a circuit perspective. In Fig. 4(a), we drew capacitors for each location inside the DRAM device structure for intuitive description.

- 4. Proposal Structure and Simulation Results: check subscripts (lines 215, 234, 287, 288, and others)

Author response: Thank you for reviewing our manuscript and your detailed comments. We missed “Si₃N₄“about subscript.

Author action: We found the wrong marked Si₃N₄ and changed it.

- 4. Proposal Structure and Simulation Results, line 167: "earlier": where?

Author response: Thank you for your kind and detailed comments. We couldn't explain clearly.

Author action: We revised to feedback your suggestion at Proposal Structure and Simulation Results section. We rewritten the corresponding sentence to clarify the explanation.

- 4. Proposal Structure and Simulation Results, line 282: what is the "old" STI?

Author response: Thank you for your kind and polite comments. We missed wrong wrote word at manuscript.

Author action: We rewrite the word "old" as "spherical."

- 5. Conclusions, line 321: how "four orders of magnitude" have been estimated as a reduction of PGE? This is not clear from the paper and this number has not been discussed in the previous part of the work.

Author response: Thank you for your kind and deep-knowledgeable comments. We did not indicate PGE reduction.

Author action: We redrawn the graph by adding the PGE reduction figure to Fig. 8(a).

- Is the spherical STI technologically possible from the point of view of the lithography process?

Author response: Thank you for your deep and knowledgeable comments. Our suggestion is that the process of dry etch, which is anisotropic, and wet etch, which is isotropic, can be adopted alternately to fabricate the spherical STI.

Author action: We added sentence at Proposed Structure to feedback your suggestion about question.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors provide a solution to reduce the Pass Gate Effect (PGE) in Dynamic Random Access Memory (DRAM). I believe this manuscript is an important contribution in the DRAM community, as many issues still need research before the technology can be largely used. The authors provide a good state of the art revision, the problem under study is well defined, the methodology, results and discussion are fine.

Despite of that, I would recommend some minor revisions before the article is considered for publication:

1. Figures should have a name. Many figures do not have a name, only a description of the subfigures.

2. In line 15, the software name is SILVACO.

Author Response

Original Article Title: “Mitigating WL-to-WL disturbance in DRAM through adopted Spherical Shallow Trench Isolation with silicon nitride layer at the BCAT”

To: Editor

Re: Response to reviewers

Dear Editor,

Best regards,

Yeon Seok Kim et al.

Reviewer: 2

Minor comments
1. Figures should have a name. Many figures do not have a name, only a description of the subfigures.

Author response: Thank you for your detailed and deep-knowledgeable comments.

Author action: We named figures about feedback your minor comments at manuscript.
2. In line 15, the software name is SILVACO.

Author response: Thank you for your kind and detailed comments.

Author action: We revised about feedback your minor comments at abstract.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Editor,

I have carefully read the manuscript you asked me to evaluate.

In the article titled “Mitigating WL-to-WL disturbance in DRAM through adopted Spherical Shallow Trench Isolation with silicon nitride layer at the BCAT”, the authors Yeon Seok Kim et al. investigated the impact of the pass gate effect (PGE) on dynamic random-access memory (DRAM) and proposed solutions to address this issue in DRAM technology using 10 nm nodes with buried channel array transistors. They employed SILVACO to simulate various DRAM configurations. The study is based on the analysis of the energy band and the examination of the impact of the dielectric constant on the buried channel array transistor (BCAT) structure. The authors suggested structural improvements related to the incorporation of their proposed spherical Shallow Trench Isolation (STI) film and silicon nitride. The topic is interesting, the analysis is correct, and the results obtained contribute to the progress of microelectronics. I recommend the publication of this article.

Comments for author File: Comments.pdf

Author Response

Original Article Title: “Mitigating WL-to-WL disturbance in DRAM through adopted Spherical Shallow Trench Isolation with silicon nitride layer at the BCAT”

To: Editor

Re: Response to reviewers

Dear Editor,

Thank you for giving us the opportunity to strengthen our manuscript with your valuable comments and queries. It's a great honor to have your review. We deeply appreciate again the times and efforts the reviewer generously shared for reviewing our manuscript. We look forward to publishing your paper as soon as possible.

Best regards,

Yeon Seok Kim et al.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors

Thank you for implementing the comments and suggestions.

I propose to accept the paper after a minor revision:

- Line 150: "replace the [something is missing here] between ...". I would check this whole sentence and rephrase it

- Line 336 & Fig. 8: please, plot in log scale if you want to show the 4 orders of magnitude decrease, because in linear scale this is not visible at all

Author Response

Original Article Title: “Mitigating WL-to-WL disturbance in DRAM through adopted Spherical Shallow Trench Isolation with silicon nitride layer at the BCAT”

To: Editor

Re: Response to reviewers

Dear Editor,

Thank you for giving us the one more opportunity to strengthen our manuscript with your kind and valuable comments and queries. It's a great honor to have your review. Our paper has been added a detailed explanations to reflect the review you presented. We deeply appreciate again the times and efforts the reviewer generously shared for reviewing our manuscript. We look forward to publishing our paper as soon as possible.

Best regards,

Yeon Seok Kim et al.

Reviewer: 1

Line 150: "replace the [something is missing here] between ...". I would check this whole sentence and rephrase it.

Author response: Thank you for your kind and deep-knowledgeable comments. We have not clarified the explanation.

Author action: We revised to feedback actively your opinions at PGE Phenomenon and Investigation section. To clarify the description, we mentioned silicon and oxide, which are substances that exist between AWL and FPWL, and wrote a sentence that these two substances can be replaced with capacitors to represent equivalent circuits.

Line 336 & Fig. 8: please, plot in log scale if you want to show the 4 orders of magnitude decrease, because in linear scale this is not visible at all.

Author response: Thank you for reviewing our manuscript and your valuable comments. We misrepresented the decreased figure.

Author action: We revised to feedback actively your suggestion at Optimization for Spherical STI section. When we checked the simulation data again, it was fourfold decrease, not 4order decrease. We rewrote the decrease figure "4orders" as "fourfold” at fig.8 and line 336.

Author Response File: Author Response.docx