摘要:

Tantalum (Ta) metal has emerged as one of the leading materials of choice for diffusion barrier applications in Cu‐damascene interconnects. For successful implementation, the microstructure, the electrical property and the surface roughness of the barrier layer have to be controlled. To satisfy such needs, atomic force microscopy (AFM) and X‐ray diffraction (XRD) techniques have been employed to monitor the surface roughness and crystal phase of the PVD Ta thin film deposited on low‐kdielectrics. XRD results show that the population of the two different Ta crystal phases, &agr; and &bgr;, depends on substrate material, surface pretreatment prior to thin film deposition and deposition conditions. AFM results reveal that surface roughness of the thin barrier layer is mainly determined by the starting substrate surface roughness. Also, AFM surface imaging discovered that each Ta crystal phase possesses a unique surface morphology. Therefore, the population of the Ta crystal phases can be crudely quantified by performing image analysis on the AFM images. The Ta phase population obtained from AFM images correlates very well with the XRD results. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622521

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

This paper presents results of nanoindentation performed on a set of silicon nano‐spring samples formed with glancing angle deposition (GLAD) technique. The load versus displacement curves were recorded to investigate the mechanical behavior of the nano‐spring structures with various column sizes and column spacings. With the combination of atomic force microscope (AFM) and nanoindentation capabilities, in‐situ observation can be carried out to determine local deformation at the nanometer scale on the sample surface. The mechanical response was found to depend on the relative dimensions of the tip with respect to the size of the silicon nano‐column. The study indicates that the mechanical behavior of the silicon nano‐column can be significantly modified by the optimization of the overall configuration and dimensions of the silicon springs. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622522

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Multi‐link statistical test structures were used to study the effect of low k dielectrics on EM reliability of Cu interconnects. Experiments were performed on dual‐damascene Cu interconnects integrated with oxide, CVD low k, porous MSQ, and organic polymer ILD. The EM activation energy for Cu structures was found to be between 0.8 and 1.0 eV, indicating mass transport is dominated by diffusion at the Cu/SiNxcap‐layer interface, independent of ILD. Compared with oxide, the decrease in lifetime and (jL)cobserved for low‐k structures can be attributed to less dielectric confinement in the low k structures. An effective modulusBobtained by finite element analysis was used to account for the dielectric confinement effect on EM. For all the ILDs studied, (jL)cshowed no temperature dependence. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622523

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A new infrared spectroscopic ellipsometer devoted to the characterization of silicon microelectronics has been recently developed at SOPRA. Its main features are the ability to measure on a small spot ( 80×200&mgr;m) with a high signal/noise ratio. A original patented optical design suppress back face reflection and insure good quality spectral measurements in the 600–7000cm−1range. Excellent signal/noise ratio allows to perform measurements in less than 30s. All automation and real time analysis are included to offer an operator orientated metrology tool. Hereafter, the instrument is presented in details, and used to characterize different kinds of low‐k dielectrics. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622524

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

We have developed a method to determine the Pore Size Distribution (PSD) of porous low‐k dielectric materials. The method is based on a modified version of Small Angle X‐ray Scattering (SAXS). We fix the incident X‐ray angle such that it is a larger angle than the total reflection critical angle for the low‐k dielectric material, and a smaller angle than the critical angle for the substrate material. The scattered X‐rays are then collected using a two dimensional position sensitive X‐ray detector. Measurements were collected on a set of porous SiLK™, organic, low‐k dielectric, films. The results are compared with Transmission SAXS (T‐SAXS) measurements collected using Synchrotron Radiation (SR) as the X‐ray source. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622525

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A novel metrology strategy has been developed and applied to characterize the complex chemical transformations which are required to form spin‐cast nanoporous low‐K materials. Surface analysis based on Time‐of‐Flight Secondary Ion Mass Spectrometry (ToF‐SIMS) has been applied in static and dynamic modes, and coupled with X‐ray Photoemission Spectroscopy (XPS), to observe the compositional and chemical bonding changes of the surface and the underlying thin film. Results show the cross‐linking of the low‐K matrix as a function of thermal processing, along with details of the evolution of porogen species that provide the template for forming nanovoids in the fully‐processed material. This approach is promising more generally for characterizing materials transformations, particularly those involving polymeric systems where ToF‐SIMS analysis of large molecular fragments represents a highly specific analytical tool. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622526

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

This paper discusses methods of characterizing pore size distributions in low dielectric constant (low‐k) films by transmission electron microscopy (TEM), comparing both conventional TEM and high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM). Methods of sample preparation were tailored to protect pore structure during cross‐sectional thinning allowing techniques similar to conventional mechanical polishing and low‐angle ion milling. Knowledge of TEM sample thickness allows quantification of pore density distributions. TEM sample thickness and quantitative image analysis methods are discussed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622527

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The continual drive for faster interconnects in integrated circuits requires the development of new interlayer dielectric materials withkvalues less than 2.2. Porous SiLK semiconductor dielectric resin was developed to achieve this low dielectric constant by introducing nanometer‐sized pores into the SiLK matrix. The development of metrology to characterize the pores in porous SiLK dielectric films is critical for successful adoption of the material in the industry, both to ensure the film attains the desired dielectric properties and to monitor pore characteristics that may impact the integration process. Due to the complex nature of the porous structure, multiple on‐wafer methods were investigated to quantify the porosity in porous SiLK dielectric films. The use of ellipsometry, small angle X‐ray scattering and atomic force microscopy to measure void fraction, pore size, size distribution, pore morphology and their uniformity across a porous SiLK film are described. Advances in these techniques and commercialization of fab‐quality X‐ray scattering tools indicates significant progress has been made in the availability of porosity metrology for porous SiLK resin films. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622528

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The principle of small‐angle neutron scattering (SANS) contrast variation is applied to characterization of nanoporous low‐k thin films. Pores are filled with mixtures of the hydrogen‐ and deuterium‐containing analogs of a probe solvent by vapor adsorption. By varying the composition of the solvent in the pores, a “contrast match” solvent composition is identified for which the scattered intensity is minimized. The contrast match solvent mixture is subsequently used to conduct SANS porosimetry experiments. In combination with information from X‐ray reflectivity and ion scattering, the technique is useful for estimating the density of the matrix (wall) material and the pore size distribution. To illustrate the technique, a porous methylsilsesquioxane (MSQ) spin‐on dielectric is characterized. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622529

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Specular x‐ray reflectivity and small angle neutron scattering were used to characterize changes in the porosity, pore size and pore size distribution on processing a polymeric low‐k material filled with 21.6 volume percent of a deuterated porogen with an average radius of 56 Å. Processing yielded a decrease in porosity to about 11 &percent;, an increase in average pore radius to 83 Å, and a narrower pore size distribution. A sample with an unusual pore structure could be easily identified. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1622530

出版商:AIP    

年代:1903

数据来源: AIP