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随着板上系统技术的发展,在较低温度下制备具有高空穴迁移率的多晶锗硅(Si Ge)薄膜具有重要的研究意义。使用波长为532 nm的绿色脉冲式激光器对多晶Si Ge薄膜进行了退火处理,并对薄膜的特性变化进行了表征。经过优化,在单脉冲激光能量为0.5 m J和10 mm/s的扫描速度下,薄膜的特性有了较大的提高。与未经过处理的薄膜相比,退火后薄膜的晶粒尺寸增大了3倍,空穴霍尔迁移率提高了4.75倍,载流子浓度提高了24.6倍,从而使薄膜的电阻率减小了两个数量级。同时,薄膜的表面形貌也有改善,表面粗糙度的均方根值从11.54 nm降低至4.75 nm。结果表明,激光退火过程中薄膜“熔化-再结晶”的过程可以显著减小晶粒中的缺陷和晶界的数量,进而改善薄膜的电学特性。因此,绿色激光退火技术在高性能多晶Si Ge薄膜晶体管制备中具有潜在的应用价值。
With the development of on-chip system technology, it is of great significance to fabricate polycrystalline SiGe films with high hole mobility at lower temperatures. The polycrystalline SiGe films were annealed by using a green pulsed laser at a wavelength of 532 nm, and the characteristics of the films were characterized. Optimized, the characteristics of the thin film have been greatly improved at single-pulse laser energies of 0.5 mJ and 10 mm / s. Compared with the untreated film, the annealed film has a threefold increase in the grain size, a 4.75-fold increase in the Hall hole mobility and a 24.6-fold increase in the carrier concentration, resulting in a decrease in the resistivity of the film Two orders of magnitude. At the same time, the surface morphology of the films also improved. The root mean square of surface roughness decreased from 11.54 nm to 4.75 nm. The results show that the thin film “melt - recrystallization ” process in the laser annealing process can significantly reduce the number of defects and grain boundaries in the grain, thereby improving the electrical properties of the film. Therefore, green laser annealing technology has potential application in the preparation of high performance polycrystalline SiGe thin film transistors.