Chemical method for manufacturing barium strontium titanate dielectric thin film on GaAs substrate

Abstract

The invention discloses a chemical method for manufacturing a barium strontium titanate dielectric thin film on a GaAs substrate, which comprises the following steps: S1, surface treatment is carried out on the GaAs substrate so as to form As atoms with a flat atomic level as a cleaning surface of an end surface; S2, a barium strontium titanate sol is prepared; S3, the barium strontium titanate sol solution prepared in the second step is dripped on the GaAs substrate obtained in the first step, and spinning is carried out; S4, drying is carried out; S5, baking pre-treatment is carried out; S6, the GaAs substrate after baking pre-treatment in the fifth step is placed in a quartz tube and in a protection atmosphere of a certain proportion, annealing treatment is carried out at a specific temperature, and the barium strontium titanate dielectric thin film is manufactured. According to the barium strontium titanate dielectric thin film manufactured by adopting the chemical method of the invention, the crystallization quality is good, the surface is flat, the dielectric performance keeps stable along with the frequency, the dielectric constant is higher than 250 in 100KHz to 1MHz range, and the manufacturing demands for metal oxide semiconductor field effect transistors can be met in the structure. 本发明公开了一种在砷化镓基片上制备钛酸锶钡介电薄膜的化学方法，包括如下步骤：S1：对GaAs基片做表面处理形成原子级平整的砷原子为终结面的清洁表面；S2：配制钛酸锶钡溶胶；S3：将上述步骤S2配制得到的钛酸锶钡溶胶溶液滴加在上述步骤S1得到的砷化镓基片上，进行甩胶；S4：干燥；S5：烘烤预处理；S6：将上述步骤S5烘烤预处理后的砷化镓基片放在石英管中通入一定比例的保护气氛中，特定温度下进行退火处理，制得钛酸锶钡介电薄膜。采用本发明的化学方法制备得到的钛酸锶钡介电薄膜结晶质量良好，表面平整和介电性能随频率保持稳定，在100KHz‑1MHz范围内，介电常数高于250，在结构上能满足金属氧化物半导体场效应晶体管器件的制作要求。