TOSHIBA REVIEW
2009. VOL.64 NO.5

  Special Reports

Innovations in Manufacturing Engineering

Overcoming Difficulties by Manufacturing Engineering Innovations
NISHIDA Naoto

Directions of Manufacturing Technologies Innovation
KUBO Tomoaki
To support putting new products on the market and to enhance the competitive power of current products with manufacturing technologies, Toshiba needs to keep making innovations in the fields of  “ Creating Advanced Manufacturing Technology Elements,”
“ Reforming of Manufacturing Operations,” and “ Strengthening of Product Design Technologies.” The directions of these innovations are the pursuit of total optimization and the development of core technologies. In the pursuit of total optimization, Design for Manufacturability (DFM) and simulation technologies become powerful tools. In the development of core technologies, the strengthening of processing technologies, the underlying technologies for product differentiation, and manufacturing technologies that are harmonized with the environment become important.

Inkjet Coating Technology
SAKURAI Naoaki/ SAWADA Yasuhiko/ FUCHIKAMI Yasuhiko
A photoengraving process (PEP) is often utilized in the manufacturing of electronic devices such as semiconductors and flat-panel displays. Although it is useful for fabricating wiring, large amounts of direct and indirect materials are consumed in the resist, exposure, development, flaking off, and other processes. An inkjet process can solve these problems, but it is difficult to apply it to mass production because even one misdirection is not permissible in device manufacturing.
Toshiba has developed an extremely stable inkjet system for electronic device production processes by developing various elemental coating technologies to overcome these issues.

Virtual Debugging System for Manufacturing Equipment Control Software Development
MIYAUCHI Takashi/ KOBAYASHI Daisuke/ FUJITA Kazuaki
The debugging of manufacturing equipment control software has conventionally been performed using actual equipment.
Going a step further, Toshiba has developed a virtual debugging system and applied it to the development of manufacturing equipment control software using virtual hardware prior to completion of the actual manufacturing equipment hardware. Moreover, we have advanced this system by adding a verification simulator in order to develop manufacturing equipment more rapidly and efficiently. The newly developed virtual debugging system has a flexible configuration of virtual hardware so that the system can be applied to various types of manufacturing equipment. We have already applied the system to our manufacturing equipment and confirmed that it can reduce the time required for software verification by 60%.

System Construction for Quality Improvement Using Manufacturing Data
KONDO Haruhiko
To enhance production quality, which is one of the key aspects of manufacturing competitiveness, it is necessary to implement quality improvement activities by providing feedback of manufacturing quality information in order to continuously optimize the manufacturing process and the product design.
To promote quality improvement activities, Toshiba has been constructing a quality control (QC) system using manufacturing data. We have confirmed the effectiveness of this system by applying it to processing production lines for products such as semiconductors and flat-panel displays, and to assembly lines for products such as hard disk drives and PCs.

Methodology to Evaluate Effects of Improvements in Production Activities Using Financial Indicators
YAMADA Shu/ KOTAKE Masahiro
The major changes taking place in rapid succession in the business environment for digital products mean that advanced production processes are required to overcome competitors and survive in the market.
With this as a background, Toshiba has developed a methodology for enterprise supply chains of digital product business units to evaluate the effects of improvements in production activities using financial indicators. This simulation model encompasses all areas of parts procurement, unit assembly, and shipping, and also includes planning and execution activities. We have successfully established an evaluation model for the entire supply chain of electric parts units that supports top-level decision-making in project planning.

TCAD Through-Simulation for Realizing Semiconductor Process DFM
ONOUE Seiji/ TERAMOTO Ryuichi/ SHIOYAMA Yoshiyuki
As semiconductor design rules have continued to shrink in recent years, advanced processes and an increasing number of process steps have become necessary and the shortening of product development periods has become more difficult. Design for manufacturability (DFM) tools such as technology computer-aided design (TCAD) have been widely applied to the device design phase in order to improve the efficiency of development. However, such tools have been insufficiently utilized in the process development phase, leading to rework and delays during prototype wafer manufacturing.
To overcome this problem, Toshiba has developed a TCAD through-simulation with models based on actual mass-production processes. This simulation makes it possible to achieve quantification of process margins without trial production and significantly reduce the product development period by quickly identifying potential development risks and performing early process optimization.

Low-Cost Wafer-Level MEMS Packaging Technologies
MIYAGI Takeshi/ OBATA Susumu/ SUGIZAKI Yoshiaki
Microelectromechanical systems (MEMS) can provide functions and characteristics that are difficult to realize in a semiconductor device. However, the market for MEMS is restricted due to the high cost of packaging to protect micro-scale moving parts and so on.
Toshiba has developed two in-line wafer-level packaging (WLP) technologies for RF-MEMS that allow cost reductions to be attained. These technologies realize encapsulation under an atmospheric pressure condition and under a vacuum condition, respectively. Applying these technologies to wafer-level production via a front-end process, we have achieved the world’s thinnest RF-MEMS multichip package of 0.8 mm in thickness by stacking a driver IC chip and a RF-MEMS chip with a thin-film hollow structure.

Design Rules for Prevention of Molding Defects in Semiconductor Packages
TANAKA Toru/ HADAME Yasuaki
There is increasing demand for higher capacity and performance as well as thinner package size for multi-chip package (MCP) memory products in order to downsize handheld devices, such as cellular phones and PCs, as well as digital home appliances. Due to the application of MCPs to various types of semiconductor devices according to users’ requirements, the package structures of MCPs have become complicated. The utilization of design for manufacturability (DFM) in the processes of MCP memory packages has therefore become essential for the production of high-quality and low-cost packages with a short lead-time.
Toshiba has developed design rules for package designers in order to prevent molding defects of MCP packages including voids, warps, and wire sweeps. Using these design rules, we have succeeded in reducing retrogression of the design process and expanding the types of MCP packages developed.

Optical Simulation Analysis for Development of Leading-Edge Electronic Devices
OKADA Naotada
In the conventional optical simulation technique used for the design of optical devices, there has been a problem that the analysis error becomes large in the case of light-emitting elements with a complicated or fine structure corresponding to the wavelength of the light. With the drastic increase in computation power, illumination analysis by tracing several million rays and vector wave analysis by solving wave equations without approximation have recently become available for practical use in the field of optical simulation.
Toshiba has applied these analysis techniques to the development of white light-emitting diodes (LEDs) for general lighting and complementary metal-oxide semiconductor (CMOS) sensors for camera modules, and confirmed that estimation of performance with high accuracy makes it possible to shorten the development period by the use of such simulations instead of trial production.

Environmentally Conscious Semiconductor Resist Stripping Technology
HAYAMIZU Naoya/ TANGE Makiko
A resist is a masking material used in the lithographic process that forms semiconductor circuits on a chip substrate. The resist must be removed after circuits are etched, which is typically done with peroxymonosulfuric acid, conventionally produced by mixing sulfuric acid with hydrogen peroxide. However, once the process is completed, there is a problem that it is difficult to recycle the sulfuric acid because of dilution by the water released as a by-product of the breakdown of the hydrogen peroxide in the mixture.
To improve the process, Toshiba, in cooperation with Shibaura Mechatronics Corporation and Chlorine Engineers Corp., Ltd., has developed a practical semiconductor single-wafer resist stripping technology that employs electrolyzed sulfuric acid. This technology allows the sulfuric acid to be recycled, as the electrolysis of sulfuric acid generates peroxymonosulfuric acid without producing water. Moreover, an originally developed boron-doped diamond electrode permits the electrolyzed sulfuric acid to be used directly without any danger. In addition, it is possible to control the stripping ability according to the various types of resist by optimizing the electrolyte parameters. This new technology makes it possible to totally eliminate the use of hydrogen peroxide and reduce the overall environmental burden of the semiconductor wet process.


  Feature Articles

Low-Contact-Resistance Electrode Technology Aiming at Application to Advanced LSIs
NISHI Yoshifumi/ KINOSHITA Atsuhiro
The downscaling of silicon (Si) transistors has progressed in order to improve the performance of large-scale integrations (LSIs). It has been argued, however, that contact resistance at the interface between the electrode metal and Si will be a serious hindrance to performance improvement in further downscaled transistors.
Toshiba has developed a new technology to segregate a second metal at the interface between a nickel silicide (NiSi) metal electrode and Si. This metal-segregation technique makes it possible to reduce the contact resistance to less than half, which will be indispensable for deeply scaled transistors of the next generation and beyond, and is expected to be a promising technology for high-performance LSIs in 2012 or later.

Molecular Resist Based on Star-Shaped Molecule
HATTORI Shigeki/ YAMADA Arisa/ ASAKAWA Koji
The shrinkage of technology node sizes in semiconductor products, such as NAND flash memories, is attributable to the development of lithographic technology. However, resolution limits and line width roughness (LWR) of photoresists are becoming problematic in advanced nanolithography. High resolution and low roughness are expected from the molecular resists because of their small molecular size and poor conjuncture of molecular chains.
Toshiba has developed a molecular resist using a new amorphous molecule instead of a conventional polymer in order to overcome these problems. Half-pitch (hp) 50 nm line-and-space (L&S) patterns could be constructed by exposing a developed molecular resist to an electron beam (EB) at an incident energy of 30 keV.

T001 CDMA2000 1xEV-DO Cellular Phone
YOSHIOKA Yuka/ SERAKU Hirokazu/ AKIYOSHI Toshinobu
In addition to multiple functions and high performance, there is an increasing need for cellular phones with distinctive features focusing on design, color variations, and so on.
As a result of this trend, Toshiba has developed the T001 CDMA2000 1xEV-DO Rev.A (code division multiple access 2000 1x evolution data only Revision A) cellular phone. The T001 offers the “ full change” custom dress-up function that allows the whole appearance of the phone to be changed by exchanging parts, menu design, dial key operation, contents, and so on. This model is also equipped with a 5.15 mega-effective-pixel autofocus (AF) high-resolution camera with an optical image stabilizer, face-detection AF technology, and a 3.1-inch wide visual video graphics array (VGA) organic electroluminescence (EL) display.

TOSGAGETM-8000A Series X-Ray Thickness Gauge
OBARA Satoshi
X-ray thickness gauges are widely used for online measurement of the thickness of plates in a steel rolling line. As the thickness of the steel has a direct effect on the yield rate of the rolling line, thickness gauge measurement data are necessary for accuracy and reliability. In recent years, there have also been increasing requirements for rapid delivery, flexible interface specifications, and low cost.
To meet these market requirements, Toshiba has developed the TOSGAGETM-8000A series X-ray thickness gauge, which is the first release of a new series of measuring instruments for rolling applications with a new interface and employing an industrial computer for data processing.

Enhancement of Fixed Mobile Convergence Services for IP-Based Exchange System
ISHIDA Masashi/ NEGISHI Kazuya/ TASHIRO Taichi/ KUBOTA Akira
Fixed mobile convergence (FMC) services, which merge mobile and fixed-line telephone services, have been widely disseminated in recent years, and communication between internal fixed phones of a private branch exchange (PBX) and the personal handy-phone system (PHS) is possible through Internet Protocol (IP)-based networks, bypassing the integrated services digital network (ISDN). However, FMC services have not been available in companies using a primary rate interface (PRI) line, which the conventional IP transit exchange-remote terminal (ITX-RT) cannot handle.
Toshiba has developed the ITX-pri system, which is an IP transit exchange system that makes it possible to add a PRI line interface to an existing IP-based exchange system. As a result, network operators are able to expand FMC services by connecting the ITX-pri system to large PBXs that support the PRI line interface.


  Frontiers of  Research & Development

Scan-Type 3D Image Capturing System
Failure Prognostics Technology for Notebook PCs