Low-Temperature Preparation and Properties of Ferroelectric Thin Films Using Excimer UV Irradiation

Bi_4Ti_3O_<12>（BIT）铁电薄膜在非易失性铁电随机存储器（NvFRAM）中的应用得到了广泛的研究。与SrBi_2Ta_2O_9（SBT）及其相关材料相比，BIT薄膜具有较低的晶化温度、较高的结晶度、较高的居里温度、较小的矫顽场和较大的极化强度。然而，多晶BIT薄膜的P_r值被认为低至约7-10 μC/cm ^2。近年来，稀土（Ln=La，Pr，Nd和Sm）掺杂BIT（BLnT）薄膜的研究得到了广泛的关注。本文采用化学溶液沉积法（CSD）研究了（Bi，<4-x><12>Nd）_4Ti_3O_（BIT）铁电薄膜的化学溶液制备工艺和性能，并对Bi，Nd）_4Ti_3O_（BIT）铁电薄膜的制备工艺和性能<12>进行了研究。 ...更多信息 方法使用受激准分子UV灯。本文研究了准分子紫外辐照对BNT前驱体薄膜晶化、微结构的影响。在O2气氛中对沉积的BNT前驱体薄膜进行受激准分子紫外辐照，可以有效地去除薄膜中的有机物种，提高薄膜的铁电性能。用准分子紫外光照射合成的BNT薄膜具有很强的（117）反射和无规取向，薄膜表面光滑，晶粒尺寸在100-150 nm之间。BNT薄膜在550℃低温下晶化，具有饱和的P-E磁滞回线，其Pr为12.7 μC/cm^2，Ec为88 kV/cm，疲劳寿命可达10^9次，漏电流小于3 × 10^9<-7>。少

Ferroelectric Bi_4Ti_3O_<12> (BIT) thin films are extensively investigated for applications in nonvolatile ferroelectric random access memories (NvFRAM). Compared with SrBi_2Ta_2O_9(SBT) and its related materials, BIT thin films are known to crystallize at low processing temperature with a high crystallinity and to have a large remanent polarization (P_r), a small coercive field (E_c) and a high Curie temperature (T_c). However, P_r values of polycrystalline BIT thin films were seen to be as low as approximately 7-10 μC/cm^2. Recently, rare-earth (Ln=La, Pr, Nd and Sm)-doped BIT (BLnT) thin films have been intensively investigated. In particular, Bi_<4-x>Nd_xTi_3O_<12> (BNT) thin films have been attacting great attention for their ferroelectric properties which are superior to other rare earth-doped BIT thin films.In this work, chemical solution processing and properties of ferroelectric (Bi, Nd)_4Ti_3O_<12> (BIT) thin films were investigated by the chemical solution deposition (CSD) m … More ethod using excimer UV lamp. The effects of excimer UV irradiation to as-deposited BNT precurosor films on crystallization, microstructure.BNT precursor films were deposited on Pt(200nm)/TiO_x(50nm)/SiO_2/Si substrates by the spin-coating technique using metal-organic solutions. The excimer UV irradiation onto as-deposited BNT precursor films in O2 atmosphere was greatly effective in removing organic species of the BNT thin films and improving the ferroelectric properties. The synthesized BNT thin films using excimer UV irradiation showed a random orientation with a strong (117) reflection and a homogeneous microstructure consisting f grain sizes of 100-150 nm with a smooth surface. BNT thin films crystallized at a low temperature of 550℃ through the excimer UV irradiation process and showed a well-saturated P-E hysteresis loop with a P_r of 12.7 μC/cm^2 and E_c of 88 kV/cm.Their films exhibited a relatively good fatigue endurance up to 10^9 cycles and a good leakage current property with less than 3 x 10^<-7>. Less