Hydrogen-induced degradation in ferroelectric Bi3.25La0.75Ti3O12

Abstract

Effects of forming gas annealing (FGA) were investigated on ferroelectric Bi3.25La0.75Ti3O12 (BLT) thin films fabricated by a chemical solution deposition. With the FGA up to 350 °C, the Pt/BLT/Pt capacitors showed good ferroelectric characteristics without significant degradation. As the FGA temperature was increased, a decomposition of the BLT powder sample was observed by using thermogravimetric analysis. By comparing the time-dependent weight loss of BLT with that of Bi4Ti3O12 during FGA, La doping was found to significantly impede the decomposition rate. The decomposition, especially in the (Bi2O2)2+ layers, was discussed as a hydrogen-induced degradation mechanism in the Bi-layered perovskite ferroelectrics.

Effect of Forming Gas Furnace Annealing on the Ferroelectricity and Wake-Up Effect of Hf0.5Zr0.5O2 Thin Films

“…The increase in the P r in the thinner HZO films (<10 nm) after furnace annealing at 500 °C has been previously explained by the shift in the peak position, and peak broadening effect observed in the grazing incidence X-ray diffraction (GIXRD) pattern due to grain growth and residual intrinsic in-plane tensile stress. 31 Unlike conventional ferroelectric thin films based on perovskite structure, [10][11][12][13][14][15][16]32 we do not observe any degradation of P r in the HZO thin films after furnace annealing in the FG ambient. FGA films show a higher P r than the RTA annealed, and NA films, which makes ferroelectric thin films based on HfO 2 compatible with the conventional CMOS processes.…”

“…9 Unfortunately, hydrogen damages both the PZT and SBT capacitors and they lose their polarization hysteresis characteristics. [10][11][12][13][14][15][16] Recently, ferroelectricity has been demonstrated in doped-HfO 2 [17][18][19][20][21] and a solid solution of HfO 2 -ZrO 2 22 in the presence of a capping electrode as well as in un-doped HfO 2 . [23][24][25][26] HfO 2 based ferroelectric thin films are scalable, CMOS compatible and with the matured atomic layer deposition (ALD) capability emerges out to be a strong contender for future non-volatile memory technology.…”

Data retention and low voltage operation of Al2O3/Hf0.5Zr0.5O2 based ferroelectric tunnel junctions

“…Several groups have successfully demonstrated FTJ with ON/OFF ratio over 1000 by sandwiching different ferroelectric materials, such as PZT, SBT, BFO, and BTO between metal electrodes or metal and semiconductor electrodes [8][9][10][11][12]. Unfortunately, integration of these perovskite-based ferroelectric thin films into CMOS process technology has been challenging due to the scalability limitation, smaller band gaps, degradation after forming gas anneal, and unstable interface with SiO 2 /Si [13][14][15][16][17][18][19][20][21][22]. Recently, ferroelectricity has been reported in Si-doped HfO 2 by Böscke et al [23].…”

Effect of ferroelectric and interface films on the tunneling electroresistance of the Al2O3/Hf0.5Zr0.5O2 based ferroelectric tunnel junctions

“…On the other hand, flash memory is a mainstream memory that is non-volatile but consumes more power and has a limited lifetime in comparison to FRAM [2][3][4][5][6]. However, FRAM based on perovskite materials suffer from poor scalability, CMOS incompatibility, degradation after forming gas annealing, thick buffer layers, and lower coercive field [7][8][9][10][11][12][13][14][15].…”