PMID- 31450402
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20190906
IS  - 1873-3573 (Electronic)
IS  - 0039-9140 (Linking)
VI  - 205
DP  - 2019 Dec 1
TI  - Optimization of gate geometry towards high-sensitivity AlGaN/GaN pH sensor.
PG  - 120134
LID - S0039-9140(19)30760-X [pii]
LID - 10.1016/j.talanta.2019.120134 [doi]
AB  - Open-gated AlGaN/GaN high-electron-mobility transistor (HEMT) based sensor can 
      inherently deliver a high current sensitivity (S(I)) in response to the pH 
      change. However, it remains a challenge to further improve the performance of the 
      packaged AlGaN/GaN-based sensor, due to a lack of investigation on the device 
      design optimization. In this paper, the influence of the gate geometry on the 
      device sensitivity is investigated through theoretical analysis and experiments. 
      It has been found that the key factor limiting the current sensitivity is the 
      series resistance (R(S)) of the packaged sensor. There are two cases: (1) when 
      the aspect ratio of the gate structure (W/L) is small, the channel resistance 
      dominates the total resistance and the current sensitivity increases with W/L; 
      (2) when W/L is large, the R(S) dominates the total resistance, the sensitivity 
      decreases with W/L. Therefore, there is an optimal W/L which can be approximately 
      reached when W/L = rho(2DEG)/R(S). Based on the guidelines, the current sensitivity 
      of the AlGaN/GaN sensor with an optimized geometry in our experiment can reach 
      157 muA/pH, which is the highest value among the packaged AlGaN/GaN-based pH 
      sensors in literature, to our best knowledge. The comparison with the Si-based 
      ISFET and the impact of the gate membrane on the sensitivity of AlGaN/GaN-based 
      sensor have also been analyzed and discussed.
CI  - Copyright (c) 2019 Elsevier B.V. All rights reserved.
FAU - Zhang, Hanyuan
AU  - Zhang H
AD  - Power Electronic Device Laboratory, Department of Electrical Engineering, 
      Zhejiang University, Hangzhou, 310027, China.
FAU - Tu, Jiawei
AU  - Tu J
AD  - Biosensor National Special Laboratory, Department of Biomedical Engineering, 
      Zhejiang University, Hangzhou, 310027, China.
FAU - Yang, Shu
AU  - Yang S
AD  - Power Electronic Device Laboratory, Department of Electrical Engineering, 
      Zhejiang University, Hangzhou, 310027, China. Electronic address: 
      eesyang@zju.edu.cn.
FAU - Sheng, Kuang
AU  - Sheng K
AD  - Power Electronic Device Laboratory, Department of Electrical Engineering, 
      Zhejiang University, Hangzhou, 310027, China.
FAU - Wang, Ping
AU  - Wang P
AD  - Biosensor National Special Laboratory, Department of Biomedical Engineering, 
      Zhejiang University, Hangzhou, 310027, China.
LA  - eng
PT  - Journal Article
DEP - 20190708
PL  - Netherlands
TA  - Talanta
JT  - Talanta
JID - 2984816R
SB  - IM
OTO - NOTNLM
OT  - AlGaN/GaN
OT  - Current sensitivity
OT  - Gate geometry
OT  - Sensitive membrane
OT  - Two-dimensional electron gas
EDAT- 2019/08/28 06:00
MHDA- 2019/08/28 06:01
CRDT- 2019/08/28 06:00
PHST- 2019/03/16 00:00 [received]
PHST- 2019/07/05 00:00 [revised]
PHST- 2019/07/08 00:00 [accepted]
PHST- 2019/08/28 06:00 [entrez]
PHST- 2019/08/28 06:00 [pubmed]
PHST- 2019/08/28 06:01 [medline]
AID - S0039-9140(19)30760-X [pii]
AID - 10.1016/j.talanta.2019.120134 [doi]
PST - ppublish
SO  - Talanta. 2019 Dec 1;205:120134. doi: 10.1016/j.talanta.2019.120134. Epub 2019 Jul 
      8.