TEMPERATURE-DEPENDENT PROPERTY MEASUREMENTS ON MULTI-ELECTRODED THIN-LAYER DIELECTRICS

A measurement system was designed and assembled for the automatic coll ection of electrical data for thin-layer dielectrics as a function of temperature. The dielectrics were deposited on platinized silicon by s ol-gel processing, and the dielectric thickness was 0.2-0.4 mum. Many (>25) surface electrodes were formed by sputtering gold through a shad ow mark, with a typical electro e size o 210 x 210 mum2. The measureme nt equipment was computer controlled, with three-axis digital stepping motors that could scan multi-electroded capacitors and collect statis tically meaningful data. The temperature-dependent properties were mea sured between -100 and 300-degrees-C as a function of frequency (100 H z to 1 MHz) and applied field strength (0-50 MV/m). Data are reported for sol-gel-derived BaTiO3, PbZrO3, and (Pb,La)(ZrTi)O3 (i.e., PLZT) t hin-layer capacitors. Capacitance values were typically 500-1000 pF, a nd the dielectric constant could be determined within a standard devia tion of +/-1.3%. Nanocrystalline BaTiO3 was found to have a dielectric constant of 210 at room temperature with no ferroelectric properties or dielectric anomalies between -80 and 200-degrees-C. Antiferroelectr ic PbZrO3 had characteristic field-forced phase transformation behavio r to the ferroelectric state with increasing bias. The field-induced p olarization was approximately 300 mC/m2 and the coercive field was 22- 28 MV/m. PLZT 8/65/35 had a dielectric constant of 556+/-7 at 25-degre es-C, 100 KHz, and 50 mV.