Sol-gel法制备Si基Bi_(3.15)Nd_(0.85)Ti_3O_(12)铁电薄膜

Preparation of Bi_(3.15)Nd_(0.85)Ti_3O_(12) Ferroelectric Thin Films on Si Substrates by Sol-gel Method

采用Sol-gel法分别在Si(100)和Si(111)衬底上制备Bi_(3.15)Nd_(0.85)Ti_3O_(12)(BNT)铁电薄膜。研究了衬底、退火温度、退火保温时间和薄膜厚度等因素对BNT铁电薄膜结晶和微观结构的影响。在500℃退火的BNT薄膜已经结晶形成层状钙钛矿相;升高退火温度(500～800℃)、延长保温时间(30～150min)、增加薄膜厚度(170～850nm),都有利于BNT薄膜晶粒长大,其中退火温度和薄膜厚度是影响晶粒长大的关键因素;每次涂覆的厚度大约是85nm。与Si(100)衬底相比,由于Si(111)与BNT薄膜具有更好的晶格匹配,因此BNT薄膜在Si(111)衬底上更容易结晶。

Bi3.15Nd0.85 Ti3Ol2 （BNT） thin films were prepared on Si（100） and Si（lll） substrates by sol-gel method. The effect of substrate, annealing temperature, holding time and film thickness on the crystallization and microstructure for BNT films were investigated. When the BNT film was annealed at 500℃, the bismuth-layer-struc- tured pervoskite phase was formed. With increasing the annealing temperature （500-800℃）, holding time （30-150 min） and film thickness （170-850nm）, the grain sizes of BNT films increased. The annealing temperature and film thickness were important factors for the grain growth. The thickness of each layer was about 85 nm. Compared with BNT films prepared on Si（100）, the BNT films were more easily crystallized on Si（111） substrates due to better lattice matching between Si（111） substrate and BNT films.