Properties of stacked SrTiO3/Al2O3 metal–insulator–metal capacitors

Abstract

Articles you may be interested inVoltage linearity modulation and polarity dependent conduction in metal-insulator-metal capacitors with atomiclayer-deposited Al2O3/ZrO2/SiO2 nano-stacks Influence of precursor chemistry and growth temperature on the electrical properties of SrTiO 3 -based metalinsulator-metal capacitors grown by atomic layer deposition J. Vac. Sci. Technol. B 29, 01AC04 (2011); 10.1116/1.3525280 Impact of crystallization behavior of Sr x Ti y O z films on electrical properties of metal-insulator-metal capacitors with TiN electrodes Appl. Phys. Lett. 97, 162906 (2010); 10.1063/1.3505323 Atomic-layer-deposited Al 2 O 3 -Hf O 2 -Al 2 O 3 dielectrics for metal-insulator-metal capacitor applications Appl. Phys. Lett. 87, 053501 (2005); 10.1063/1.2005397Low temperature crystallization of high permittivity Ta oxide using an Nb oxide thin film for metal/insulator/metal capacitors in dynamic random access memory applicationsThe possibilities to grow thin films of SrTiO 3 and Al 2 O 3 by atomic layer deposition for stacked metal-insulator-metal capacitors have been investigated in this work. In order to tune the functional properties of the capacitors, different processing steps have been employed to realize different combinations of the dielectric stacks. Electrical properties, extracted after the postdeposition annealing and sputter deposition of the Au top electrodes, indicated that the metal-insulator-metal (MIM) structures with additional Al 2 O 3 layer provided better leakage currents densities, compared to the ones with single SrTiO 3 based MIM capacitors, but the dielectric constant values have also decreased if additional Al 2 O 3 film was inserted. Attempts to optimize the properties of the MIM stacks have been done by manufacturing heterostructures of Al 2 O 3 /SrTiO 3 /Al 2 O 3 as well as SrTiO 3 /Al 2 O 3 /SrTiO 3 . In the first case, Al 2 O 3 prevented the crystallization of SrTiO 3 in the multilayer dielectric structure and therefore reduced the total capacitance density of the particular MIM stack, whereas the SrTiO 3 /Al 2 O 3 /SrTiO 3 stack was found to possess superior electrical properties. Leakage current density as low as $10 À8 A/cm 2 at 2 V and the dielectric constant value of 40 have been extracted.

Dielectric Material Options for Integrated Capacitors

“…The effects of the location of the leakage current blocking layer within the stack have been published elsewhere. 31 As evident from Figure 1, there are generally two different voltage regions with varying gradients within the leakage current density graph. Thus first a comparison of leakage current density of the investigated dielectrics was generated for the low-voltage region.…”

Impact of composition and crystallization behavior of atomic layer deposited strontium titanate films on the resistive switching of Pt/STO/TiN devices

“…For the conformal growth on three dimensional (3D) structured devices with high integration density, chemical vapor deposition techniques 29,30 and, in particular, ALD techniques, 15,31,32 were utilized. Although the requirements on the aspect ratio of 3D structures for ReRAM applications are still moderate, the future of high-density ReRAM will also be defined by more challenging 3D topologies.…”

Characterization of ALD Ta2O5, Al2O3, and Ta2O5/Al2O3 Nanolaminate as Metal-Insulator-Metal Capacitor Dielectric for GaAs HBT Technology

“…However, the dielectric constant of this PECVD silicon nitride is relatively low and ranges only from 6 to 7, depending on the deposition chemistry and condition (10,12,14,19). Recently, studies have been performed to investigate the use of atomic layer deposition (ALD) method to deposit MIM capacitor dielectric material in semiconductor technologies (4,11,(20)(21)(22). Most of these studies were performed on Si technologies, and only a few have been performed on GaAs technologies.…”

“…Most of these studies were performed on Si technologies, and only a few have been performed on GaAs technologies. This ALD method has been used to deposit films with high dielectric constant at low temperatures with excellent conformality and uniformity, and with good chemical, physical, and electrical characteristics (21)(22)(23)(24)(25). Furthermore, it has been reported that ALD nanolaminate of two or more materials can be tailored, adjusted, and controlled in order to obtain a film with all the characteristics that are desired and required (26)(27)(28)(29)(30).…”