Monthly Archives: February 2016

Too soon for deep-UV steppers

Because Perkin-Elmer Corp may be bought by Japanese interests, the situation for VLSI integrated circuit production technology in Japan and the US is becoming more interesting. Japanese manufacturers have bet on deep-UV technology for manufacturing VLSI integrated circuits, and have pursued development of deep-UV steppers, photoresists and lasers.

Meanwhile, US manufacturers’ gradual transition to I-line for submicron technology has proved unexpectedly successful. The Japanese had maintained that I-line was not practical to use. The key for US companies is to push I-line technology as far as possible before the Japanese make deep-UV equipment ready and available. Perkin-Elmer Corp, which may be bought by a Japanese firm, is a US company developing a deep-UV stepper.

Now that Perkin-Elmer Corp., Menomonee Falls, Wisc., is for sale and may be bought by Japanese interests, it makes for an interesting situation regarding VLSI IC production technology in the U.S. and Japan. While equipment manufacturers in both countries press on toward the next technology level, Japanese chip makers may have waited too long to pursue an interim step that many U.S. companies took. The result: U.S. chip makers may find themselves, for the meantime, with an unexpected technology edge.

As recently as 1985, 1-[micrometer] design rules were considered state of the art for advanced VLSI production. Optical equations predicted that 0.5 [micrometer] was the resolution limit. Today, however, manufacturing is shifting from G-line lithography, with its 436-nm exposure source, to I-line, which sports a 365-nm source.

These new frontiers in line widths for VLSI circuits are the result of polymer chemistry as well as the associated optics. Polymer chemists are now placing the limit at 0.25 [micrometer]. They’re making no promises, though, because theoretically, the line widths can’t go beyond the wavelength of the I-line exposure source, which is 365 nm, or 0.36 [micrometer]. The next level is a deep-UV exposure source, which is 254 nm. In theory, this could take lines and spaces down to about 0.25 [micrometer]. But it’s probably a year or two from viability.

Apparently, Japanese manufacturers of VLSI ICs are looking to 0.25 [micrometer] for next-generation VLSI devices, which is a factor-of-four density increase compared with 0.5-[micrometer] I-line. Those companies have bet heavily on deep-UV and have hotly pursued development of deep-UV steppers, lasers, and photoresists. Meanwhile, I-line has become unexpectedly successful and gained a new life. Essentially, it was written off too soon, especially by the Japanese chip makers who maintained that I-line was unpractical due to its 0.5-[micrometer] limit. Meanwhile, deep-UV became more difficult to develop than was believed.

Concurrent with their drive toward deep-UV, the Japanese tried holding their technology edge by pushing G-line lithography to its limit by improving the optics. Indeed, they took G-line farther than anyone thought possible and achieved much tighter production parameters than U.S. companies. But because U.S. companies weren’t able to push G-line as far as Japan, they promoted the more gradual transition to I-line as a viable strategy for submicron lithography. As a result, U.S. companies gained a small technology edge. The key, now, will be to get as far ahead as possible with I-line before deep-UV is ready and viable, and before the Japanese shift gears and catch up in I-line.

But Japanese manufacturers are already on the move. Nikon, San Bruno, Calif., is one Japanese-based company that got to market with an I-line stepper by recently introducing its NSR-1755i7 A. Moreover, Nikon claims to have the largest exposure area available in an I-line stepper (17.5 mm square) as well as a production resolution of 0.58 [micrometer]. European companies are also joining the I-line parade. ASM Lithography, based in Tempe, Ariz., but owned by Philips, the Netherlands, rolled out its PAS 5000/50 I-line stepper and claims 0.50-[micrometer] production resolution and 0.35-[micrometer] resolution for research work. ASM also has a deep-UV machine in progress.

Among U.S. manufacturers, Perkin-Elmer is developing a deep-UV stepper. GCA, Andover, Mass., is marketing its AutoStep 200 I-line stepper and is working on a deep-UV machine. Sematech, the Austin, Texas-based consortium, is concentrating on I-line lithography, but is committed to transferring a well-characterized 0.5-[micrometer] process to its member companies by 1991.

KTI Chemicals, Sunnyvale, Calif., (a Union Carbide subsidiary) already offers its 895i I-line photoresist product. It’s betting that I-line will be the way to go because deep-UV will require a massive equipment investment. But just in case, KTI has a deep-UV photoresist in the works.

VHDL simulator supports 100% of the DOD standard

Silicon Compiler Systems (SCS) introduces Explorer VHDLsim, an IEEE 1076-1987 VDHL standard-compliant simulator. VHDLsim is integrated into SCS’s Explorer Lsim mixed-signal, multilevel simulation environment, giving engineers transparent access to resources including the Mach 1000 accelerator and Spice simulation. VHDLsim provides both the M and VDHL languages for engineers who choose to use analog and digital behavioral modeling. Mixing analog and digital modeling in the same simulation enables the inclusion of VHDL in mixed-signal designs. Explorer VHDLsim will be available in second quarter 1990 at a cost of $30,000 if purchased as an option to Explorer Lsim. A standalone version will be priced at $42,000.

Because of its heavy backing by the U.S. government and the IEEE, VHDL should make its mark on the CAE industry during the next few years. That’s made clear by the flurry of VHDL activity among simulation vendors. The latest to announce VHDL simulation support is Silicon Compiler Systems (SCS).

SCS supports the IEEE’s 1076-1987 VHDL standard with Explorer VHDLsim, a simulator that’s integrated into the company’s Explorer Lsim mixed-signal, multilevel simulation environment. The new simulator’s most important feature is its 100% support of the language, including behavioral, structural, and data-flow levels. Moreover, users can simulate VHDL models from any source.

Another key feature is the simulator’s meshing with the larger Lsim environment. That means, for example, users can have transparent access to resources such as the Mach 1000 accelerator and Spice simulation. Because the Explorer Lsim environment can simulate from the architectural level all the way down to the Spice level, the top-down design process need not stop at the gate level. Structural VHDL models may be simulated at the gate-, switch-, and circuit-levels in Explorer VHDLsim. This is possible because users won’t need to change simulation environments to get their designs in shape.

In cases where designers choose to use analog and digital behavioral modeling, the simulator gives them both the M and VHDL languages, respectively. M is a superset of the C language and is used for both digital and analog behavioral modeling. Because M is a full programming language, proprietary simulation algorithms may also be added. Translations from M into VHDL will be supplied where possible for those users with extensive libraries written in M and who need to document these models in VHDL.

By mixing analog and digital models in the same simulation, designers can include VHDL in mixed-signal designs as well as in pure digital designs. In addition, with VHDLsim there’s no performance penalty for using the VHDL language.

For accurate timing simulation, users will be able to run mixed-signal simulations using device-level representations where that level of accuracy is needed, and VHDL behavioral or gate-level models everywhere else. This includes mixed-signal simulation using HSpice and VHDL by means of the Lsim/HSpice interface that SCS has developed with MetaSoftware Inc., Campbell, Calif.

SCS’s Explorer Lsim environment comes with an interactive, source-level symbolic debugger that will be used for both VHDL models and models written in the M hardware-description language (see the figure). Other benefits of the tight integration with SCS’s design-automation products include schematic capture, synthesis, and other front- and back-end tools. “Integration is something that SCS can bring to the party that other standalone VHDL suppliers can’t,” claims James Griffeth, director of product marketing for SCS.

As if 100% support of the standard wasn’t enough to make VHDLsim stand out, it’s also distinguished by its performance. The simulator uses SCS’s direct-compilation technology, which is much faster than simulators using interpretive-language technology. This is because the VHDL code is compiled directly into C rather than a proprietary hardware-description language.

As a result of its alliance with CAD Language Systems Inc. (CLSI), Rockville, Md., VHDLsim includes CLSI’s VHDL Tool Integration Platform (VTIP), a set of front-end design-capture tools. As far as users are concerned, a simple pushbutton operation compiles source code into an executable circuit model. First, the code comes in through the CLSI VHDL parser, which parses it into the intermediate format. After that, the code is automatically accessed and optimized by VHDLsim, which compiles it directly into C. The resulting C object files are then further optimized by the C compilers native to the designer’s workstation.

Explorer VHDLsim supports the ability to do incremental compiling and dynamic loading. During a given simulation, designers may wish to modify one of the behavioral models in the hierarchy. An incremental compilation recompiles just the model that was changed, which is much faster than recompiling or reinterpreting the entire environment. Those recompiled models can be dynamically loaded without having to leave the simulator, which saves a great deal of time. That’s because users avoid simulation start-up time as well as the overall compile time or reinterpretation time.

According to Griffeth, SCS achieved 100% support of the VHDL language so quickly because of its four years of active participation in the IEEE’s VHDL standardization movement. As a result, the company had access to many of the leading-edge VHDL concepts as they took shape and heeded their architectural implications.

Surface mounting will sweep leaded components from market

The 1990s will see a continuation of the changeover from leaded to surface-mounted devices, which save money because of their small size, which cuts costs by saving space on computer boards, and through greater reliability and lower handling costs. Currently, surface-mounted devices account for 50 percent of the passive components used in Japan. That figure is 13 percent in North America and 10 percent in Europe. Leadless passive component use in North America will pass 50 percent over the next five years, and Europe will not be far behind. Surface-mount devices will continue to improve, offering ever-better tolerances, capacitance-voltage product, stability, and higher frequencies.

The most important component trend in the 1990s will continue to be the worldwide changeover from leaded to surface-mounted devices. As component users get smarter, they inevitably switch from leaded components to surface-mounted devices, wherever possible, for the simple reason that they save money. Because of their small size, surface-mounted devices save space on pc boards, which cuts costs. In addition, they’re more reliable and they cost less to handle. I also expect them to become less expensive than leaded components.

Not surprisingly, Japan is the leader in the use of surface-mounted devices. Whereas only 10% of the passive components used in Europe are surface-mounted devices, over 50{ of them are in Japan. In North America, the figure is about 13%. Over the next five years, I expect that leadless passive components used in North America will rise past 50%, with Europe to follow suit. The overwhelming trend is toward surface mounting, and anyone who hasn’t made the transition should plan on starting soon.

For potential users of surface-mounted devices who aren’t sure how to start, there are assembly operations that do subcontracting work. Many small and medium-sized companies go to such assemblers to get their designs established, and later they bring the work inside. Large companies also use outside contractors to smooth out the peaks and valleys in their production schedules. High-speed equipment for placing surface-mounted devices is somewhat expensive, and not even a giant corporation wants to have this gear just sitting around.

As time goes on, I expect these devices to get better and to become more popular and less expensive. For the components that I’m most familiar with–tantalum capacitors–“better” takes on many definitions. It means more reliable parts with tighter tolerances and better stability; packing more CV (capacitance-voltage product) into a given volume; lowering the cost per CV; and the ability to work well at ever higher frequencies.

When I went to school, the basic electrolytic capacitor was an aluminum device with a tolerance of -20% and +50%, or even +100%. Today, we’re routinely making tantalum units with tolerances of [+ or -]5%, even [+ or -]2% can be done on special order. Tighter tolerances can be expected in the near future. These capacitors can be used for timing and waveform-shaping applications, not just for power-supply filtering and decoupling. That was simply unthinkable for an electrolytic capacitor in the past.

We’re also making specials in which the variation of capacitance with temperature and frequency is tightly controlled. That capability is opening up new applications for tantalum capacitors–both in displacing other capacitor types and in areas that never existed before, such as fiber optic communications. We can expect other types of electrolytic capacitors to also open up even more applications.

The latest tantalum electrolytics are also maintaining their capacitive nature at increasingly high frequencies. They present a lower equivalent series resistance (ESR) and remain reactive at frequencies up to about 1 MHz, a figure that will undoubtedly increase during the next decade. Therefore, they can better serve their intended function–decoupling.

A major function of the electrolytics is to filter out power-supply noise. With today’s switches running at 100 to 500 kHz, they’re often operated near the limits of their capabilities, but they continue to deliver their intended outputs.

Working at the edge, however, can be tricky. Applying electrolytic capacitors at high frequencies requires expert knowledge, which brings us to another important element for the next decade–service. Component makers not only need to make better components, they need to deliver them precisely when the customer wants them. They also must supply all of the required technical support. To help with the latter requirement, we’re writing and compiling a series of simple capacitor application programs that can run on a PC. Our intention is to make those programs available to users along with our catalog.

Then designers, at their own leisure, can choose a part from the catalog, key in their operating parameters, and get, for example, a plot of ESR vs. frequency. The whole objective is to make it easier for people to use and understand the components.

Giving Futons A Better Name

If Sean Pathiratne has his way, the word “futon” will gradually fade from the home furnishings lexicon.

Pathiratne is president of Lifestyle Solutions Inc., a major manufacturer of futon frames. His choice of words: “sofa-bed convertible.” In fact, that’s what he now calls his product in his promotional literature. To Pathiratne, “futon” too often conjures up the image of the disposable, cheap contraption used by college students.

Low-cost futons will continue to occupy a niche on the floors of mass merchants and warehouse clubs. But if the futon category expects to gain acceptance with high-end consumers and traditional retailers that have so far shied from this category, the products and image will have to be more upscale — and challenge the cumbersome fold-out sleeper sofa, according to Pathiratne. Other manufacturers of futon products are starting to think along those same lines and devoting more effort to quality workmanship and the promotion of style.

Furniture stores are a key part of this plan, according to Pathiratne. “Furniture stores are the next frontier,” he said. “For furniture stores that sell sofas and sofa beds and move the customer up, this is perfect for them.”

Some of the more forward-thinking furniture stores, such as R.C. Willey and HOM, are starting to offer futons as potential alternatives to these best sleeper sofas. The appeal for a consumer? Easy conversion from sitting to sleeping; high-style, hardwood frames; a mattress that rivals a conventional bed; a rainbow of covers that can be changed with the seasons. Add to that the fact that a futon is lighter and less cumbersome to move and suddenly the whole aging boomer and retirement categories are interested.

Tony Wolf, president of Wolf Corp., a futon mattress manufacturer, launched a Serta-licensed futon line last year, which could add to both consumer and retailer appeal. He sells to the retailer both a frame and a futon mattress, which is then sold under the Serta name. A retailer eager to limit its suppliers now has the opportunity to buy these two components from one source

Bob Naboicheck, president of Gold Bond Mattress Co., a family-owned manufacturer of futon mattresses and conventional innerspring mattresses, expects futon sales to continue to climb. He cited the “bang for the buck” factor during a soft economy.

“In any soft or down market where customers are looking more for value, futons will excel,” Naboicheck said. “I think futon sales will continue to outpace upholstered sleep sofas, daybeds and the other alternatives that one would have for a convertible sit-and-sleep product. Our futon business has been phenomenal, especially in the upgraded, better [futon] mattresses. You can go from a Yugo to a Rolls Royce in a futon for maybe a hundred dollars.”

But making that same jump in quality in the innerspring category would be several hundred dollars, he added.

Advantages for the retailer? He enjoys the sale of a product that rivals a $499 sleeper sofa in price, and the easily removable fabric covers offer a constantly changing floor display.

And those covers are a big part of the push. John Christiansen, customer service manager at SIS Covers Inc., a manufacturer of futon covers, has seen a sharp upswing in the quality of covers demanded by consumers. Leather covers, for the first time, are making a dent in the market. A consumer can get the look of a $3,000 leather sofa for a fraction of that cost. Fabric covers, too, offer fashion statements, as contemporary patterned fabrics with a rainbow of colors and hues take off. Futon stores still have the lion’s share of business, but the improved quality and styling of the covers has turned the heads of a growing number of mainstream furniture stores and mattress shops, Christiansen added.

Assuming the futon industry does go more upscale in 2003, who’s going to get that business? Independent futon shops have been the innovators and spear carriers for quality futon products thus far, but, according to one vendor, “they can’t rest on their laurels.” Dilution at the retail level for quality merchandise will continue to grow, and the same independents that have been the anchors for the futon industry could see their business erode if more retail furniture chains sell the big-profit, low-inventory, high-end products.

Otis Bed Manufacturing Inc., a producer of futon mattresses as well as conventionally shaped foam mattresses, broadened its retail presence by going into Costco warehouses, as well as continuing its existing retail base at the middle to upper price ranges.

“It helps bring more positive awareness of futons to consumers,” said Karen Day, director of sales and marketing for Otis Bed. As a board member of the Futon Association International, she is trying to give the word “futon” a more upscale connotation.

“I think there needs to be more awareness that they really are a viable, functional piece of furniture you can have in your home for years,” Day said. “Dealers should not be afraid of the price. They should just go for it. Try it. But if they do jump into it, they should get a good mix and don’t be afraid of the higher ticket items because you will sell it.” Retailers also need to understand that the three-component makeup of a futon (frame, mattress, cover) with its array of options for a consumer can work for them.

“They find it a little bit difficult to put the whole thing together,” she said.

For 2003, Day expects futons to continue to get more upscale, as latex, viscoelastic foam and other premium products get used more. She also thinks that better-engineered futon frames, such as Otis’s Futonic adjustable electric massage unit, will gain in acceptance.