Thao N. Nguyen

High-field-induced degradation in ultra-thin SiO/sub 2/ films

Very thin thermal oxides are shown to exhibit a failure mode that is undetected by conventional breakdown tests. This failure mode appears in the form of excessive leakage current at low field and is induced by high-field stresses. The stress-induced oxide leakage is permanent and stable with time and thermal annealing. It becomes the dominant failure mode of thin oxides because it always precedes destructive breakdown. Experimental results and theoretical calculations show that the leakage current is not caused by positive charge generation and accumulation in the oxide. It is proposed that the oxide leakage originates from localized defect-related weak spots where the insulator has experienced significant deterioration from electrical stress. The leakage conduction mechanism appears to be thermally assisted tunneling through the locally reduced injection barrier, and the model seems to be consistent with both I-V measurements at temperatures from 77 K to 250 degrees C and theoretical calculations. >

Longitudinal media for 1 Gb/in/sup 2/ areal density

Media with low noise at high transition density that demonstrate satisfactory recording performance at an areal density, of 1 Gb/in/sup 2/ when combined with dual-element (magnetoresistive read/inductive write) heads have been fabricated. A media structure of C/CoPtCr/Cr was utilized over a range of magnetic parameters: coercivity approximately=1600-1800 Oe, remanence-thickness product approximately=0.7*10/sup -3/ emu/cm/sup 2/, and coercive squareness approximately=0.7-0.8. Media noise reduction was accomplished by optimizing the film-growth characteristics to reduce intergranular exchange coupling in the magnetic layer. The low-noise characteristics of the media are manifested in their low transition jitter values, 5 nm for 3- mu m track width, and the absence of supralinear increase in media noise power with linear density up to 3000-3500 fc/mm. The -6-dB rolloff densities are in the range 4000-5000 fc/mm. Overwrite values are typically better than 40 dB. Microstructural analysis indicates that the reduced transition noise of the present media is due to physical separation of the grains in the magnetic films, which reduces the exchange coupling between the magnetic grains. The reduced coercive squareness of the low-noise media degrades the overwrite performance and is also expected to decrease the linear density resolution of the media. >

A Software as a Service with Multi-tenancy Support for an Electronic Contract Management Application

In most commercial electronic contract management applications available today, different customized code base has to be developed, deployed and operated to support each tenant. Few advanced commercial electronic contract management applications use a single code base with configuration options to support multi-tenants. However, a separate instance of the code base still has to be deployed and operated for each tenant even in these applications. The business model of having to support a single application instance for each tenant makes an electronic contract management application and other critical business applications out of reach for most small and medium businesses (SMBs), in particular, the very small businesses (SVBs) because of its high development and maintenance cost. Recently, a new business model of a single application instance supporting multi-tenancy based on software as a service (SaaS) has emerged making expensive business applications more affordable for SMBs and SVBs for multi-tenancy [1]. In this paper, we present the first of a kind multi-tenancy SaaS electronic contract management application. We also describe several novel methods used in the metadata, security and shared services, as well as customization and tenant extensions modules to support multi-tenancy SaaS in this application. This multi-tenancy SaaS application has shown to benefit both the application service providers as well as their tenants. This new multi-tenancy SaaS model can reduce the application hosting cost and make the application more affordable to the tenants because of its capabilities in customization and scalability while continuing to support an increasing number of tenants. It furthers benefits tenants by saving their money and time with immediate access to the latest IT innovations and infrastructure improvements on a single application code base. Most end users of tenants have found their productivities increased, the contract transaction time accelerated, contractual errors reduced in using this multi-tenancy SaaS electronic contract management application as demonstrated in several ongoing IBM pilot programs serving more than ten tenants with over 3000 end users.

A gate-quality dielectric system for SiGe metal-oxide-semiconductor devices

The authors present a high-quality dielectric system for use with Si/sub 1-x/Ge/sub x/ alloys. The system employs plasma-enhanced chemical vapor deposited (PECVD) SiO/sub 2/ on a thin (6-8-nm) layer of pure silicon grown epitaxially on the Si/sub 1-x/Ge/sub x/ layer. The buffer layer and the deposited oxide prevent the accumulation of Ge at the oxide-semiconductor interface and thus keep the interface state density within acceptable limits. The Si cap layer leads to a sequential turn-on of the Si/sub 1-x/Ge/sub x/ channel and the Si cap channel as is clearly observed in the low-temperature C-V curves. The authors show that this dual-channel structure can be designed to suppress the parasitic Si cap channel. The MOS capacitors are also used to extract valence-band offsets.<<ETX>>

Oxide-thickness determination in thin-insulator MOS structures

A technique to electrically determine the oxide thickness (and, in some cases, the flat-band voltage and surface doping as well) of thin-insulator MOS structures is discussed. This method does not require a model for either the accumulated or inverted semiconductor interface but assumes only that the classical MOS theory holds for zero surface band bending. By means of numerical simulations and comparison with high-resolution measurements obtained with transmission-electron microscopy, the technique is found to be valid well beyond the conditions for which it has been mathematically derived and to be applicable in almost all cases of practical interest. >

Role of atomic mobility in the transition noise of longitudinal media

The relationship between grain growth morphology and the transition noise of high-density CoPtCr media on Cr underlayers is examined. The growth morphology is shown to depend on the sputtering pressure, substrate bias, and substrate temperature. Development of isolated magnetic grains is promoted when the mobility of the sputtered atoms is reduced, i.e. at high sputtering pressure, low substrate temperature, and no substrate bias. As the magnetic grains become more isolated, the media transition noise is significantly reduced, accompanied by a simultaneous reduction in the coercive squareness. This indicates that the transition noise is primarily governed by the intergranular exchange coupling among the magnetic grains, which can be optimized by controlling the grain growth morphology. The microstructural features of the decoupled media correspond to the zone I structure in J.A. Thorntons (1986) microstructure zone diagram. >

The role of spin‐dependent impurity scattering in Fe/Cr giant magnetoresistance multilayers

To probe the mechanism of giant magnetoresistance (GMR) observed in Fe/Cr multilayers, we have sputter deposited at the interfaces of Fe(15 A)/Cr(12 A) multilayers an additional, ultrathin (0–4 A) layer of a variety of third elements (V, Mn, Ge, Ir, and Al). When alloyed with Fe in dilute concentrations, the elements chosen have known resistivities for spin‐up (ρ↑) and spin‐down (ρ↓) currents arising from spin‐dependent impurity scattering. The results show a clear correlation between α=ρ↓/ρ↑ of the respective element and the way in which GMR varies with the ultrathin layer thickness. In addition, little difference in GMR is observed between multilayers where the ultrathin layer thickness t/2 is deposited on every Fe/Cr interface and those with a thickness t deposited on alternate interfaces. This investigation demonstrates the importance of the type and total number of scattering centers per multilayer period to the GMR effect.

Business-to-business integration with tpaML and a business-to-business protocol framework

In business-to-business interactions spanning electronic commerce, supply chain management, and other applications, the terms and conditions describing the electronic interactions between businesses can be expressed as an electronic contract or trading partner agreement (TPA). From the TPA, configuration information and code that embody the terms and conditions can be generated automatically at each trading partners site. The TPA expresses the rules of interaction between the parties to the TPA while maintaining complete independence of the internal processes at each party from the other parties. It represents a long-running conversation that comprises a single unit of business. This paper summarizes the needs of interbusiness electronic interactions. Then it describes the basic principles of electronic TPAs, followed by an overview of the proposed TPA language. The business-to-business protocol framework (BPF) provides various tools and run-time services for supporting TPA-based interaction and integration with business applications. Finally, we describe examples of solutions constructed using TPAs and BPF.

The Coyote Project: Framework for Multi-party E-Commerce

The Internet provides the opportunity for quickly setting up deals between businesses for promoting each others products, and to jointly offer new services. Specification and enforcement of such deals stretch traditional transaction processing concepts in several directions since they involve independent businesses with their own internal processes. First, the greater variability in response time in business to business interaction creates a need for asynchronous and event-driven processing, in which correct handling of reissued and cancelled requests is critical. Second, a new transaction processing paradigm is required that supports different views of a unit of business for all participants, i.e., service providers as well as end consumers. Between any two interacting parties, there may be several related interactions dispersed in time, creating a long running conversation. This paper describes our approach (Coyote) to solving these problems including use of a service contract for specifying the rules of interaction across businesses, and directly generating code for enforcement of the contract. We finally describe the architecture and a prototype of a system which implements the Coyote concepts.

Secure Search of Private Documents in an Enterprise Content Management System

An enterprise content management system such as an electronic contract system manages a large number of secure documents for many organizations. The search of these private documents for different organizational users with role- based access control is a challenging task. In this paper, we present a novel content-based XML-annotated secure-index search mechanism that provides an effective search and retrieval of private documents with document-level security. The search mechanism includes a document analysis framework for text analysis and annotation, a search indexer to build and incorporate document access control information directly into a search index, an XML-based search engine, and a compound query generation technique to join user role and organization information into search query. Our experiments on a pilot electronic contract system demonstrate that, by incorporating document access information directly into the search index and combining user information in the search query, search and retrieval of private contract documents can be achieved very effectively and securely with high performance.