A Comprehensive Characterization
of Stress Relaxed ZnO Thin Film
at Wafer Level
Priyanka Joshi, Jitendra Singh, V. K. Jain and Jamil Akhtar
Abstract The chapter goes onto explore the impact of sputtering parameters on
structural, optical, and mechanical properties of reactive magnetron sputtered ZnO
thin film. Stress relaxed and room temperature deposited ZnO film is highly desirable
from fabrication aspects. Oxygen partial pressure is varied from 30 to 60% and c-axis
oriented ZnO (002) thin films are prepared at room temperature. The stress varies
in −0.06 × 10
9 to −2.27 × 10
9 dyne/cm
2 range, and compressive in nature. A
detailed characterization of ZnO sputtered film is carried out in order to correlate the
mechanical, structural, and optical properties of thin film. A theoretical model has
been proposed to understand the consequences of oxygen-induced stress in ZnO thin
films. It is established that nearly stress-free, single-phase, and highly c-axis oriented
ZnO thin film can be deposited using a unique combination of sputter parameters.
Keywords Zinc oxide · Characterization · Stress · Sputtering · Oxygen partial
pressure
1 Introduction
Zinc Oxide (ZnO) is a versatile material and exhibits semiconducting, optical
and piezoelectric properties (Ozgur et al. 2005) Micro-electro-mechanical systems
(MEMS) based devices require ZnO thin films as a functional layer for sensing and
actuation applications. ZnO can be integrated into variety of devices such as acoustic
resonators, sensors, optical waveguides and microwave filters (Wang and Song 2006;
Joshi et al. 2018, 2019). Stress relaxed and room temperature deposited ZnO film is
highly desirable from fabrication aspects (Baraki et al. 2014; Fu et al. 2010; Gardeniers et al. 1998). Further, ZnO is a green material and compatible to semiconductor
P. Joshi (B) · J. Singh · J. Akhtar
Smart Sensors Area, CSIR-Central Electronics Engineering Research Institute, Pilani 333031,
Rajasthan, India
e-mail: piyujsh@gmail.com
P. Joshi · V. K. Jain
College of Engineering and Technology, Mody University, Lakshmangarh 332311, Rajasthan,
India
© Springer Nature Switzerland AG 2020
L. Ledwani and J. S. Sangwai (eds.), Nanotechnology for Energy and Environmental
Engineering, Green Energy and Technology,
https://doi.org/10.1007/978-3-030-33774-2_21
495
of Stress Relaxed ZnO Thin Film
at Wafer Level
Priyanka Joshi, Jitendra Singh, V. K. Jain and Jamil Akhtar
Abstract The chapter goes onto explore the impact of sputtering parameters on
structural, optical, and mechanical properties of reactive magnetron sputtered ZnO
thin film. Stress relaxed and room temperature deposited ZnO film is highly desirable
from fabrication aspects. Oxygen partial pressure is varied from 30 to 60% and c-axis
oriented ZnO (002) thin films are prepared at room temperature. The stress varies
in −0.06 × 10
9 to −2.27 × 10
9 dyne/cm
2 range, and compressive in nature. A
detailed characterization of ZnO sputtered film is carried out in order to correlate the
mechanical, structural, and optical properties of thin film. A theoretical model has
been proposed to understand the consequences of oxygen-induced stress in ZnO thin
films. It is established that nearly stress-free, single-phase, and highly c-axis oriented
ZnO thin film can be deposited using a unique combination of sputter parameters.
Keywords Zinc oxide · Characterization · Stress · Sputtering · Oxygen partial
pressure
1 Introduction
Zinc Oxide (ZnO) is a versatile material and exhibits semiconducting, optical
and piezoelectric properties (Ozgur et al. 2005) Micro-electro-mechanical systems
(MEMS) based devices require ZnO thin films as a functional layer for sensing and
actuation applications. ZnO can be integrated into variety of devices such as acoustic
resonators, sensors, optical waveguides and microwave filters (Wang and Song 2006;
Joshi et al. 2018, 2019). Stress relaxed and room temperature deposited ZnO film is
highly desirable from fabrication aspects (Baraki et al. 2014; Fu et al. 2010; Gardeniers et al. 1998). Further, ZnO is a green material and compatible to semiconductor
P. Joshi (B) · J. Singh · J. Akhtar
Smart Sensors Area, CSIR-Central Electronics Engineering Research Institute, Pilani 333031,
Rajasthan, India
e-mail: piyujsh@gmail.com
P. Joshi · V. K. Jain
College of Engineering and Technology, Mody University, Lakshmangarh 332311, Rajasthan,
India
© Springer Nature Switzerland AG 2020
L. Ledwani and J. S. Sangwai (eds.), Nanotechnology for Energy and Environmental
Engineering, Green Energy and Technology,
https://doi.org/10.1007/978-3-030-33774-2_21
495