Furqan Mehmood

Technische Universität Dresden | TUD · Nanoelectronics

Further optimization of a typically reported ferroelectric capacitor comprised of a Hf0.5Zr0.5O2 ferroelectric thin film with TiN electrodes is explored by introducing an additional non‐ferroelectric La2O3 interfacial layer evaluated at different positions in the capacitor stack. The role of the interface to the ferroelectric layer is investigated...

We have studied the field cycling behavior of microscopic TiN/Hf 0.5 Zr 0.5 O 2 /TiN ferroelectric capacitors using synchrotron-based soft x-ray photoemission electron microscopy. The oxygen vacancy ([Formula: see text]) concentration near the top TiN/Hf 0.5 Zr 0.5 O 2 interface is estimated from the reduction of Hf ⁴⁺ to Hf ³⁺ as measured in the H...

В последнее время обнаружено наличие сегнетоэлектрических свойств наноразмерных пленок на основе оксида гафния. Такие пленки представляют большой интерес для разработки универсальной памяти, которая сочетает преимущества оперативной и флэш-памяти. В работе изучаются оптические свойства пленок оксида гафния-циркония Hf x Zr y O 2 и пленок оксида гаф...

Recently ferroelectric properties have been found in hafnia-based nanosized films. Such films are of the utmost interest for development of a universal memory, which combines the advantages of random access memory and flash memory. The paper studies optical properties of hafnia-zirconium oxide films Hf x Zr y O 2 and lanthanum-alloyed hafnia-zircon...

HfxZr1-xO2 and lanthanum-doped HfxZr1-xO2:La thin films are candidates for applications in ferroelectric random-access memory. Here, we explore the atomic and electronic structure of Hf0.5Zr0.5O2 and Hf0.5Zr0.5O2:La thin films grown by atomic layer deposition. Using X-ray photoelectron spectroscopy, it was found that the oxides under study have an...

Lanthanum-doped HfZrO is considered as the ferroelectric material for capacitor structures used in one-transistor-one capacitor nonvolatile memory cells for the development of new generation nonvolatile random-access memory. Here, different capacitor structures are characterized by x-ray photoelectron spectroscopy electrically to determine the elec...

Since the discovery of ferroelectricity in thin doped hafnium oxide layers, there is a rapidly growing interest in the implementation of this material into non‐volatile memory devices like ferroelectric capacitors, transistors, or tunnel junctions. In most cases, a field cycling induced change of the remanent polarization is attributed to wake‐up a...

Multiple polymorphs coexist in doped HfO2 ferroelectric material, and their relative fraction depends on the dopant concentration. The ferroelectric properties originate only from the polar orthorhombic Pca21 phase, which can be stabilized in a binary mixture of HfO2 and ZrO2 at a low thermal budget. However, this material suffers from limited fiel...

We present a hard and soft x-ray photoelectron spectroscopy study of the interface chemistry in pristine TiN/La-doped Hf0.5Zr0.5O2/TiN capacitors. An oxynitride phase (∼1.3 nm) is formed at the top interface, while a TiO2−δ phase was detected near the bottom interface. The oxygen vacancy (VO) concentration is higher at the top interface than in the...

After the discovery of ferroelectricity in HfO2, many dopants have been incorporated into the material to improve the ferroelectric properties. The binary mixture of HfO2 and ZrO2, HfxZrx−1O2, showed the widest process window in terms of polarization, but other memory related aspects still need improvement. Recently, the co‐doping of La into a mixe...