In this paper, the kinetics of Ni metal induced lateral crystallization (MILC) in a Si channel has been thoroughly investigated. The impact of excess Ni supply, high-and-long thermal treatments, and fast ramp rate annealing on the quality of Si channel formed are reported. We show that it is possible to achieve up to 10 times higher mobility, and enhanced channel control with a controlled MILC process compared to a regular polysilicon channel.

We evaluate the reliability of Mo as word line metal for 3-D NAND Flash devices, by mimicking the stacked architecture using planar capacitors with SiO2/Al2O3 and SiO2/HfO2 dielectric stacks. By combining TDDB and TVS measurements with simulations, we show that Mo does not drift in the two examined stacks. Moreover, our study highlights the importance of controlling the defectivity at the Sithfhigh-k interface and within the high-k to avoid the risk of early dielectric breakdown.

We demonstrate the integration of Ruthenium (Ru) and Molybdenum (Mo) as Word Line (WL) metals in a record 40nm pitch 3D-NAND device through an optimized Replacement Metal Gate (RMG) process. The optimized RMG process minimizes oxide regrowth which affects WL fill capability in reduced pitches. Ru and Mo gates show better resistivity (ρ) and memory characteristics compared to the currently used Tungsten WL. We demonstrate good channel control and program/erase (P/E) characteristics down to 20nm WL. Best P/E is obtained for Mo with 2nm HfOx liner after a post metallization anneal (PMA) at 750°C for 20mins, while devices with Ru WL show better retention.

We demonstrate the integration of Ruthenium as Word Line metal in a 3-D NAND device by adopting the Replacement Metal Gate (RMG) process. Ruthenium gate shows better resistivity compared to currently used Tungsten and improved memory characteristics compared to what is obtained with a TiN electrode. Overall best performance is obtained with a 2 nm ZrO2 liner / Ru stack, followed by a 750 °C anneal.

Electrical nanoprobing inside scanning electron microscopy (SEM) systems has become a routinely used characterization technique for electrically measuring prototypes of the most advanced nanoelectronics device structures. Tungsten wire needles with a sharpness of about 50-100 nm are commonly used as probe tips in these measurements. They suffer unfortunately from tip oxidation effects and need to be initialized. Moreover, they are too soft to directly probe on semiconductor materials such as Si and Ge. Therefore, harder probe tips are required which can withstand high pressures (in GPa range) and oxidation. In order to meet these requirements, we have developed doped diamond tips and integrated them into metal cantilevers. They have an in-plane geometry which allows direct visibility in the SEM system of both the area to be contacted and the tip apex. Furthermore, the probes are mounted at the end of a metal wire which ensures compatibility with existing nanoprobing systems and allows for convenient probe handling. This paper describes the probe concept and discusses the probe fabrication process in detail. Manufactured probes are presented and their suitability for measurements on a Ge calibration structure is demonstrated. Our work shows that the developed diamond nanoprobes overcome the disadvantages of existing tungsten wire probes and enable the probing of semiconductor materials. (C) 2014 Elsevier B.V. All rights reserved.

We report on the performance and reliability of the Hf/HfO2 RRAM cell with Ultra-Thin Oxide (UTO-RRAM). We show that cells with an oxide thickness of 3 nm have basic performance (including speed, switching voltages, and the on/off window) similar to that of the cells with reference oxide (5-10 nm thickness), while their operation requires a forming step at a voltage of only about 1.5 V for a 40 nm size. This performance can be further optimized by tuning the cap layer thickness. We also demonstrate endurance of at least 108 cy and observe failure modes similar to the reference cells. Endurance optimization needs to take into account, next to the stack structure and pulse characteristics, the target on/off states. UTO-RRAM retention is strongly temperature-activated, with a median cell extrapolating at 125°C/10 yr. Furthermore, we analyze in detail the on-state loss and show how emergence of tail bits relates to the strength (initial level) of the state.