Ferroelectric memory: state-of-the-art manufacturing and research

Abstract

Semiconductor industry calls for emerging memory, demonstrating high speed (like SRAM or DRAM), nonvolatility (like Flash NAND), high endurance and density, good scalability, reduced energy consumption and reasonable cost. Ferroelectric memory FRAM has been considered as one of the emerging memory technologies for over 20 years. FRAM uses polarization switching that provides low power consumption, nonvolatility, high speed and endurance, robust data retention, and resistance to data corruption via electric, magnetic fields and radiation. Despite the advantages, market share held by FRAM manufacturers is insignificant due to scaling challenges. State-of-the-art FRAM manufacturing is studied in this paper. Ferroelectric capacitors and memory cells made by main commercial FRAM manufactures (Texas Instruments, Cypress Semiconductor, Fujitsu и Lapis Semiconductor) are explored. All memory cells are based on the lead zirconate titanate PZT capacitor with the thickness of about 70 nm and IrOx/Ir or Pt electrodes. The leading FRAM technology remains the 130 nm node CMOS process developed at Texas Instruments fabs. New approaches to further scaling and new devices based on ferroelectrics are reviewed, including binary ferroelectrics deposited by ALD techniques, piezoelectronic transistors, ferroelectric/2D-semiconductor transistor structures, and others. Whether FRAM technology will be able to resolve one of the main contradictions between a high-speed processor and a relatively slow nonvolatile memory depends on the success of the new technologies integration.

Ultrafast Polarization Switching in BaTiO3 Nanomaterials: Combined Density Functional Theory and Coupled Oscillator Study

“…A potential physical mechanism for write operation is magnetization switching by an ultrashort electromagnetic pulse of optical or THz range. This mechanism has been shown promising in previous studies. − Similarly, electric fields can be utilized for ultrafast polarization switching in ferroelectric materials. Although this possibility has garnered significant attention, it has not yet been observed experimentally.…”

“…amu /fs2 . This (F th ) is equivalent to the acceleration a 2 , which represents the acceleration of the Ba + ion created by the electric field of such a field is linked to fluence…”

Формирование И Исследование Структур Металл--Диэлектрик--Полупроводник На Основе Пленок Оксида Гафния

“…На сегодняшний день лидером на рынке энергонезависимых устройств памяти является флэш-память, использование которой, однако ограничено сравнительно медленной скоростью работы и низким числом возможных переключений [1]. В отличие от флэш-памяти, устройства памяти на основе сегнетоэлектриков, напротив, обладают потенциально неограниченным ресурсом и высокой скоростью чтения и записи [2,3]. Сегодня единственные коммерчески доступные устройства сегнетоэлектрической памяти -это устройства с произвольным доступом FRAM, причем в качестве функционального слоя используются сегнетоэлектрики типа: Pb[Zr x Ti 1−x ]O 3 , SrBi 2 Ta 2 O 9 , BiFeO 3 , обладающие рядом недостатков, связанных с высокой чувствительностью к границе раздела и стехиометрии, а также малым смещением зоны проводимости по отношению к уровню Ферми кремния, что ограничивает возможность создания сегнетоэлектрической памяти, совместимой с современной кремниевой технологией [4].…”

Two-dimensional WSe2 flakes under high power optical excitation

“…The explosive interest in such structures is primarily due to their unique properties, including the presence of a direct nonzero bandgap, real two-dimensionality, chemical and thermal stability, and flexibility. The possibility of these materials' application in various fields of nano-and optoelectronics, from logic devices [1,2] and memory cells [3,4] to biosensors [5] and gas sensors [6], has been demonstrated.…”