Local crystallographic texture and voiding in passivated copper interconnects

A correlation between local crystallographic texture and stress‐induced void formation in tantalum‐encapsulated, copper interconnects was revealed by electron backscattering diffraction studies in a scanning electron microscope. Lines exhibiting an overall stronger 〈111〉 texture showed better resistance to void formation. Furthermore, grains adjacent to voids exhibited weaker 〈111〉 texture than grains in unvoided regions of the same line. The locally weaker 〈111〉 texture at voided locations suggests the presence of higher diffusivity, twist boundaries. This work, which represents the first characterization of local texture in stress voided, copper lines, helps to elucidate the relative importance of the thermodynamic and kinetic factors which govern void formation and growth. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70319/2/APPLAB-69-26-4017-1.pd

CoWBP capping barrier layer for sub 90 nm Cu interconnects

Abstract Electroless cobalt films have been obtained by deposition using a plating bath containing two reducing agents: dimethylamineborane (DMAB) and sodium hypophosphite. This formulation allows spontaneous activation on copper followed by auto catalytic electroless plating. CoWBP and CoBP films are proposed as diffusion barriers and encapsulation layers, for copper lines and via contacts for ULSI interconnect applications. The crystalline structure, chemical composition and oxidation states of the elements were studied, as well as the electrical resistivity, topography and morphology of the films. The film composition was characterized as a function of the solution composition; the barrier properties of the films were tested and an oxidation resistance study was conducted. The films were characterized and the results show that they can be applied as capping layers for ULSI copper metallization

In-vivo monitoring for electrical expression of plant living parameters by an impedance lab system

We present a complete in-lab system to monitor the plant and its surrounding environment. The plant impedance is directly measured in a continuous manner, while, simultaneously surrounding environment parameters known to affect plant status, are monitored. This is done combining a new in-vivo direct measurement of the plant together with an embedded system using available sensor technology and a designated interface for continuous data acquisition. Furthermore, the next versions this system can be deployed as a field monitoring device, with simple adaptations

Analysis of in Vivo Plant Stem Impedance Variations in Relation with External Conditions Daily Cycle

World population growth and desertification are the most severe issue to agricultural food production. Smart agriculture is a promising solution to ensure food security. The use of sensors to monitor crop production can help farmers improve the yield and reduce water consumption. Here we propose a study where the electrical impedance of green plants' stem is analyzed in vivo, along with environmental conditions. In particular, the variations associated with the daily cycle are highlighted. These analyses lead to the possibility of understanding plant status directly from stem impedance

Electrochemical study and material characterization of electroless CoNiWPB thin films

Electroless plating of thin NiCo alloy films The chemical properties of both Ni and Co, as related to the electroplating bath, are similar. Both metals sulfate salts are widely used in plating, they are deposited from similar baths using similar complexing agents, they both can be deposited with refractory metals and both yield very high quality films. Although the alloys of either Co or Ni alloys are now better understood In this work we present the results of an electrochemical study of the deposition of electroless NiCo alloys with tungsten from a bath containing DMHB and sodium-hypophosphate as reducing agents, 3-sodiumcitrate acid as a complexing agent, and minute amount of HCl. The solution pH was adjusted to 9.4-9.6 at T=60-80C.. The films were deposited on (100) single crystalline Si, activated by self assembled monolayer using AminoPropyl-Tri Amino Silane (APTES) followed by Pd activation I-E polarization curves were measured for the cathodic and anodic reactions (using Hg/Hg 2 Cl 2 reference electrode). We measured the mixed potential and deposition current as a function of the bath composition. The measurements were taken in baths with two reducing agents (DMAB & NaH 2 PO 2 ) while varying the Co, Ni and W concentration. We show that the tungsten concentration has a minor effect on the electrochemical parameters; however, it has a significant effect on the composition. We studied samples annealed at various temperatures using XRD and resistivity monitors. The XRD of samples annealed at elevated temperatures, above 400C, identified pure silicides, including NiSi and CoSi, and more complex phases such as W 2 Co 21 B 6 (see Finally, we summarize the work and discuss the tungsten deposition mechanisms and their effect on the film properties. We conclude that the surface adsorption mode

Microstructure and material properties of electroless CoWP films obtained from sulfamate solutions

This work describes the development of a thin film cobalttungsten–phosphorous (Co–W–P) alloy, deposited from an electroless deposition solution and the study of the effect of the solution composition and deposition parameters on the microstructure, electrical and magnetic properties of the deposits. Electroless deposition of CoWP was performed on copper surface from novel electroless bath with cobalt sulfamate Co(NH 2 SO 3 ) 2 as a source of Co ions and sodium tungstate as a source of tungsten. The reducing agent and a source of phosphorous was sodium hypophosphite. The developed electroless solution produces high quality cobalt alloy films with the ability to form 2–2.5 μm thick soft magnetic layers. The CoWP deposition rate was found to decrease with the increase of sodium tungstate concentration. The maximum tungsten content in the film was about 1.9 at.%. The influence of the tungsten concentration in the solution and postdeposition vacuum annealing on film morphology, surface topography, composition, magnetic properties and resistivity was studied. The resistivity of the CoWP layers shows a strong nonlinear dependence on the film thickness. The resistivity of the asdeposited films was in the order of 10−4 Ω cm and it decreased by about a factor of two after vacuum annealing at 400 °C for 2 h. The corresponding evolution of the film structure and morphology is presented and discussed. The CoWP deposit demonstrated high temperature stability up to 350 °C during annealing in air