Back-Channel Etched In-Ga-Zn-O Thin-Film Transistor Utilizing Selective Wet-Etching of Copper Source and Drain

Round 1

Reviewer 1 Report

In the manuscript, the authors have investigated Cu and Mo/Cu S/D on the electrical properties of IGZO TFTs. There are few data in this manuscript, and there is no characterization of the Cu and Mo/Cu films, and TFT stability. Therefore, it is impossible to analyze the front- and back-channel interfaces of the active layer and the resistance between IGZO and the S/D electrodes. So far, many literatures have reported the effect of S/D electrode on TFT performance, what is the novelty of this find the innovation of this manuscript? There is no evidence of Cu electrode diffusion, such as TLM analysis. Moreover, the English of this manuscript needs to be polished. 

Author Response

Dear Reviewer,

Here I have attached the point-by-point response in the attachment. Please see the attachment.

Thank you very much for your kind cooperation.

Sincerely yours,

Rauf Khan

Author Response File: Author Response.docx

Reviewer 2 Report

In this work, the Mo/Cu S/D electrodes of IGZO TFT was etched with non-acidic special Cu etchant. Although the electrical characteristics of IGZO TFT was well, the stacked structure of S/D was not novelty in IGZO TFT and the special of “non-acidic special Cu etchant” were not explained clearly, so, it hardly seems that this work provides outstanding originality and novelty.

The comments on this work are listed as follows.

• In line 69, the value of channel width and length are inconsistent with those shown in Figure 3.
• The plotting scale should be added in Figure 3.
• In line 44, author mentions that “we investigated the performance of IGZO TFTs with Mo/Cu/Mo S/D electrodes…”, however, the only IGZO TFTs with Cu (Sample A) and Mo/Cu (Sample B) S/D electrodes were fabricated.
• The author should provide the composition of “special Cu etchant” and explain the difference between “special Cu etchant” and “acidic Cu etchant”. To prove the effect of “special Cu etchant”, the author should also provide the electrical characteristics of IGZO TFT which etched with “acidic Cu etchant”.
• The author claimed that the diffusion of Cu into IGZO layer lead to the degradation of the electrical characteristics of sample A after annealing. The elemental analysis of IGZO layer before and after annealing should be given to prove this conclusion.
• Table 1 lack of a table caption.

Author Response

Dear Reviewer,

Here, I have attached the point-by-point response to the attachment. Please see the attachment.

Thank you very much for your kind cooperation.

Sincerely yours,

Rauf Khan

Author Response File: Author Response.docx

Reviewer 3 Report

see the attached file

Comments for author File: Comments.docx

Author Response

Dear Reviewer,

Here, I have attached the point-by-point response to the attachment. Please see the attachment.

Thank you very much for your kind cooperation.

Sincerely yours,

Rauf Khan

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The author has made modifications to the questions raised and basically reached the level of acceptance, but there are still some small problems in the manuscript, such as spelling errors, subscripts in the figure, and the English of the manuscript.

Author Response

Dear Reviewer,

Hope you are doing well.

Here, I have attached the reply to the comments of the review report (Round 2).

Please refer to the attached file.

 

Thank you very much for your kind cooperation.

 

Sincerely yours,

Rauf Khan

Author Response File: Author Response.docx

Reviewer 2 Report

The author responded to our comments in detail, and the novelty of this work has also been discussed adequately. Therefore, I recommend this article can be accepted after minor revision.

Minor corrections:

Line 165, figure 6 instead of figure 5

Author Response

Dear Reviewer,

Hope you are doing well.

Here, I have attached the reply to the comments of the review report (Round 2).

Please refer to the attached file.

 

Thank you very much for your kind cooperation.

 

Sincerely yours,

Rauf Khan

Author Response File: Author Response.docx

Reviewer 3 Report

This manuscript reports a low contact resistance IGZO TFTs with copper source and drain. The Mo interfacial layer blocks Cu from diffusion to IGZO, but Mo/Cu structure is not a novel idea, many early reports have already been published. Non-acid etchant seems to be the main focus of this paper. However, the analysis of the experiment of the etchant and the responses to my previously some comments are also insufficient. Therefore, this paper can not be accepted for publication in Processes. Moreover, there are still some issues that need to be carefully addressed and are summarized as follows:

 

1. Answer 2 shows the microscopic image after using Mo etchant, it said that Mo etchant will damage the TFT device structure, but in this paper, it focused the special Cu etchant. I think the comparison of the transfer curves with special Cu etchant and conventional etchant are necessary to clarify the improvement mechanism.
2. Answer 4 shows the transfer curve with NBS, but it is necessary to show a comparison to devices with and without passivation layer, respectively.
3. In the new version of the paper, the layout is dislocation, e.g., Figure 4 and Table 1.

Author Response

Dear Reviewer,

Hope you are doing well.

Here, I have attached the reply to the comments of the review report (Round 2).

Please refer to the attached file.

 

Thank you very much for your kind cooperation.

 

Sincerely yours,

Rauf Khan

Author Response File: Author Response.docx