항온항습 환경에 노출된 Al2O3 ALD 박막의 특성 평가

Abstract

In this work, we evaluated the Al2O3 film, which was deposited by atomic layer deposition, degraded by exposure to harsh environments. The Al2O3 films deposited by atomic layer deposition have long been used as a gas diffusion barrier that satisfies barrier requirements for device reliability. To investigate the barrier and mechanical performance of the Al2O3 film with increasing temperature and relative humidity, the properties of the degraded Al2O3 film exposed to the harsh environment were evaluated using electrical calcium test and tensile test. As a result, the water vapor transmission rate of Al2O3 films stored in harsh environments has fallen to a level that is difficult to utilize as a barrier film. Through water vapor transmission rate measurements, it can be seen that the water vapor transmission rate changes can be significant, and the environment-induced degradation is fatal to the Al2O3 thin films. In addition, the surface roughness and porosity of the degraded Al2O3 are significantly increased as the environment becomes severer. the degradation of elongation is caused by the stress concentration at valleys of rough surface and pores generated by the harsh environment. Becaused the harsh envronment-induced degradation convert amorphous Al2O3 to crystalline structure, these encapsulation properties of the Al2O3 film was easily degraded.