[E-1] Emerging Thin Film Devices and Technologies

[E-1-05] pH Sensing Enhancement for ALD High-k Membrane By Stack Structures and Post annealing In LAPS

〇Jiun Han Yen¹, Yu Cheng Yang², Nai Chuan Chen^1,2, Chia Ming Yang^1,2,3,4 (1. Inst. of Electro-Optical Engineering, Chang Gung Univ. (Taiwan), 2. Department of Electronic Engineering, Chang Gung Univ. (Taiwan), 3. Department of Nephrology, Chang Gung Memorial Hospital (Taiwan), 4. Department of Materials Engineering, Ming-Chi Univ. Tech. (Taiwan))

Presentation style: On-site (in-person)

https://doi.org/10.7567/SSDM.2022.E-1-05

The atomic deposition system (ALD) is one of the best methods to deposit high-k oxide thin films and the stacked structure, which can greatly improve the stability of the device performance. Therefore, a high-quality pH sensing membrane constructed by the stack structure with Al2O3 and HfO2 nm-scale films in-situ layer-by-layer process by ALD system is proposed in this study. The total thickness of this stack structure is 24 nm, which is composed with Al2O3 and HfO2 layer with thickness of 6 and 6 nm for 2 cycles in sequence. In this fabricated sensing membrane on Si-based light-addressable potentiometric sensor (LAPS), an N2 RTA treatment at 400℃ was used to improve the hydrogen ion sensitivity, linearity, hysteresis and drift to be 54.9 mV/pH, 99.9%, 4.16 mV and -0.35 mV/h, respectively. This superior pH sensing performance can be recommended to apply in the field-effect sensors.

Keywords — Al2O3, HfO2, high-k, LAPS, photo current, RTA, stacked structure