Transistor performance is a key enabler for state‐of‐the‐art electronic devices. Besides fast switching performance, low power consumption is a critical parameter for mobile products. The implementation of HfO2 as a gate dielectric with a high permittivity reduces leakage current and power consumption drastically. Metal gates and work function materials are required to adjust Fermi levels and are essential for device performance. In addition to these key elements of high‐k metal gate (HKMG) technology, encapsulation liners and spacers are found to have a significant impact. We show that the performance of HKMG transistors has a strong dependency on the film quality and growth conditions of the SiN spacers. A good conformality and excellent step coverage at low deposition temperature is achieved with an atomic layer deposition (ALD) process using dichlorosilane and ionized radicals of ammonia. This ALD process is superior to standard LPCVD and PECVD processes with regards to thickness control, within‐wafer‐uniformity and matching of the thickness values between dense and isolated transistors. ALD SiN is applied as a spacer to define the implant profiles. The impact of the ALD SiN spacers on transistor universal curve, miller capacitance and Vt is demonstrated. Further application is a hard mask for selective epitaxy of SiGe. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

No abstract

In this paper we highlight through two examples the potential of zeolitic host materials for the production of totally engineered macroscopic-scale electronic structures that are made up of vast arrays of reduced dimensionality subunits. Through a novel contactless microwave cavity technique we have investigated the electrical conductivity and dielectric properties of a mesoscopic assembly of ultrafine (atomic-scale) wires of potassium prepared within a highly structured aluminosilicate matrix, zeolite L. We have observed an increase in room-temperature conductivity of around 5 orders of magnitude relative to unmodified zeolite, which may be ascribed to thermally activated electronic conduction. In our second example, a combined X-ray/EXAFS study has provided valuable insights into the reduction process involved in the preparation of nanoscale ferromagnetic cobalt particles in zeolite X. In addition, detailed calculations of cation solvation energies represent the first attempt to explain the driving force behind the two important and related chemical processesnamely the dissolution of elemental metals and ionic salts in dehydrated zeolitesused to incorporate metal species into the zeolite matrix in these two cases.

Recent work1 has highlighted the possibility that through the introduction of metals into the one-dimensional channels of zeolite L, it may be feasible to engineer charge transport along the channels to produce a unique compound comprising a precise, assembled array of ultrafine, atomic-scale conducting wires embedded within the aluminosilicate framework. Using electron spin resonance (ESR), and microwave cavity perturbation measurements, we examine the properties of these remarkable materials as a function of composition as they approach the insulator to metal transition.