Brian W. Kempshall

Effects of diffusion induced recrystallization on volume diffusion in the copper-nickel system

The effects of diffusion induced recrystallization (DIR) on volume diffusion in the Cu(Ni) system was investigated. Cu-Ni diffusion couples annealed at 500, 550, 600, and 650 °C for 120 and 200 h were used to calculate the volume diffusion for the Cu(Ni) binary system. Using characterization techniques such as focused ion beam (FIB) and transmission electron microscopy (TEM), observation of the interdiffusion zone revealed areas containing DIR and nonDIR. The volume diffusion of Ni into Cu across the non-DIR regions were calculated using the Boltzmann-Matano (B/M) method at 1 wt% Ni to be 8.05E-21, 9.88E-20, 4.53E-19, 2.67E-18 m 2 /s for 500, 550, 600, and 650 °C, respectively. Calculations of volume diffusion across the DIR zones were approximately three to four orders of magnitude higher than the volume diffusion based on the non-DIR information. Literature values for volume diffusion in the Cu(Ni) system are also higher than the non-DIR values by approximately one order of magnitude, implying that previous values may contain grain boundary contributions.  2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.

Ion - Solid Interactions

In this chapter we summarize reactions that take place when an energetic ion impinges on a target surface. The results based on equations that are usually used to estimate ion range and ion sputtering in amorphous materials are presented. A discussion on ion channeling and ion damage in crystalline materials is presented. The problems of redeposition associated with an increase in sputtering yield within a confined trench are presented. Knowledge of ion - solid interactions may be used to prepare excellent quality FIB milled surfaces.

Utilizing the SIMS technique in the study of grain boundary diffusion along twist grain boundaries in the Cu(Ni) system

The secondary ion mass spectrometry (SIMS) technique was used to study grain boundary diffusion along (100) twist grain boundaries in the Cu(Ni) system. Concentration profiles of Ni down Cu twist grain boundaries with nominal disorientation angles of 10°, 5 (36.87°), and 45°, were measured using the SIMS technique. The average activation energy for grain boundary diffusion, Qb, was found to be 245 ± 22, 140 ± 10, and 102 ± 15 kJ / mol, for the 10°, 5, and 45° twist grain boundaries, respectively. The average grain boundary diffusion pre-exponential term, sdDbo, was found to be 9.6 ± 1.24 × 10 9 , 1.1 ± 0.17 × 10 14 , and 1.3 ± 0.36 × 10 16 m 3 / s, for the 10°, 5, and 45° twist grain boundaries, respectively.

Grain boundary segregation: equilibrium and non-equilibrium conditions

The segregation of Bi to Cu grain boundaries can be characterized as either equilibrium or non-equilibrium segregation. The experimental conditions of the segregation process determine the type of segregation behavior that is achieved. Classical McLean equilibrium segregation can be achieved through Bi grain boundary segregation from a constant vapor source with long anneal times. The Chang dislocation-pipe diffusion model of Bi segregation more accurately describes the onset of Bi segregation from an instantaneous source for short anneal times. A discussion on the conditions defining Bi segregation behavior is presented. 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.

EFTEM Contrast Tuning and EELS Fine Structure Analysis for Characterization of Carbon Containing Ultra-Low-k Dielectric Materials

Miniaturization of transistors is but a single leg of the race to improve speed in integrated circuits (IC). Interconnect is equally as crucial to the performance of advanced technology node devices. As production devices are emerging at the 14nm node, there is a corresponding and necessary reduction in interconnect pitch. Blazing fast processing speeds and densely packed routing intensifies the imperative to use advanced ultra-low-k (ULK) dielectric materials to reduce the RC time delay, minimize crosstalk and lower power consumption. Technological evolution has ushered in the integration of progressively lower dielectric constant materials starting with fluorinated dense materials through carbon-laden polymers, organically modified SiOx and into the era of porous silicate materials with incorporated organic species. While these porous insulators have proven to perform admirably, there are concurrent collateral complexities for process integration and as well as for characterization. These materials are less thermally and mechanically robust than their traditional SiOx predecessors. Nevertheless, the reliability of the IC is dependent on the ability of the dielectric to maintain its integrity through the severe processing steps and beyond. A multitude of characterization opportunities are generated by the use of ULK materials in the interlevel dielectric (ILD) and the required complex support network of films for diffusion barrier, adhesion, etch stop to name a few.

Energy-dispersive x-ray spectrum simulation and emprical observation of 22nm node high-k metal gate structure

Characterization of advanced technology node integrated circuits is an ever-increasing challenge. In order for analytical capabilities to keep pace with technology it is important to carefully consider all aspects in the design and execution of experiments. It is essential to be able to distinguish artifact from meaningful data and to recognize the limitations as well as the capabilities of a given technique. Some critical considerations include specimen preparation, physical limitations of the instrumentation, alignment and calibration as well as user selected acquisition parameters. The effects of sampling size, signal to noise ratio, specimen geometry, instrumentation and accelerating voltage on the microanalysis of multilayered metal gate structures created using atomic layer deposition (ALD) are presented.