Influence of homo-buffer layer on stress control of sputtered (Ba0.45,Sr0.55)TiO3 thin films on Pt-Si

TL;DR

This study investigates how a homo-buffer layer influences stress relaxation and reduces hillock formation in sputtered (Ba0.45,Sr0.55)TiO3 thin films on Pt-Si, leading to improved electrical properties.

Contribution

It introduces a homo-buffer layer method to eliminate Pt hillocks and control stress in BST thin films, enhancing film quality and electrical performance.

Findings

Homo-buffer layers above 5 nm prevent Pt hillock formation.

BST films with 15 and 25 nm buffer layers show good electrical properties.

Buffer layers improve stress relaxation and film quality.

Abstract

To engineer strain relaxation of sputtered BST thin films on Pt-Si wafers, homo-buffer layer method was applied to eliminate Pt hillock formation. Thin BST homo-buffer layers were deposited at room temperature and subsequently the main BST layer was deposited at 650{\deg}C, Pt hillock free BST films were obtained with homo-buffer thickness above 5 nm. Relatively good electrical properties were obtained for BST thin films with 15 and 25 nm homo-buffer layer (T= 30 % at 5V and tan {\delta}= 0.018).