SEL EXHIBIT 2019
`
`INNOLUX CORPORATION v. PATENT OF SEMICONDUCTOR ENERGY
`
`LABORATORY CO., LTD.
`
`IPR201 13-00066
`
`

`

`Ion Beam Etch Technology
`
`The Cutting Edge of Ion Beam Etch and Thin Film Technology
`
`i»
`A
`
`~ QuickDelivery
`SuperiorQuality - Aggressive Pricing
`
`TECHNOLOGY
`
`l
`Hi
`
`Substrate Properties
`Common Films
`Design Guide
`
`Technology
`Etch Rates
`
`Wayne M. Stauss, MicroFab, Manchester, New Hampshire
`Todd E. Lizotte, NanoVia, Manchester. New Hampshire
`Introduction
`The Electronics industry is demanding increased product density, increased yields and tighter tolerances. lon
`Beam Etching (IBE) technology meets these challenges by providing a capability to produce line widths and
`dense structures to micron levels. with high yields and minimal pattern variations, Pn‘ce factors have always
`made conventional isotropic chemical etch processes the dominating etching technique used in industry.
`However. Chemical etching techniques can produce lifetime limiting defects due to contamination,
`undercutting of films. chemical reactions with other materials and general surface roughening and pitting. For
`these reasons, Ion Beam anisotropic etching technology is rapidly becoming the etching technology of choice
`for many high density applications, Ottr hope is that a better understanding of ion milling will allow
`technologists the ability to apply it effectively and reliably.
`Ion Beam Source [1]
`An Ion Source generates a broad Ion Beam directed at the substrate (or product to be patterned). The most
`common broad beam source is the Kaufman (grid) type illustrated in Figure 1. Ions are generated in a
`discharge chamber where atoms of a gas (Argon) are ionized by energetic electron bombardment. Electrons
`are emitted from a cathode filament and collected by the anode. A magnetic field is used to contain the
`electrons and increase the probability of ionization. The bombardment of electrons with gas atoms forms a
`conductive gas or plasma. A negatively biased grid is used to accelerate ions that pass through the grid to
`form the ion beam. After the accelerator grid. a Neutralizer filament is used to introduce electrons to balance
`the positively charged ions. The beam current and voltage can be independently controlled to obtain the
`desired ion energy (expressed in electroanotts) and beam current density (expressed in Amperes/cmz).
`
`A vacuum of 10‘6 Torr to 10'5 Torr is accomplished with a roughing pump and a high vacuum molecular
`pump. The vacuum is required to produce the Ion Beam plasma as well as minimize contamination to the
`substrate during the etching process. A pressure of 10'4 Torr is typical while the Gas is flowing to produce the
`Ion Beam.
`
`The substrate is typically mounted onto a Rotating Stage assembly. Several axis of rotation are employed to
`achieve a uniform etch profile and to also control the angle of incidence of the ion beam.
`GAS MRI}?1)
`
`
`
`— C (“WNW
`VANCE
`
`SUBS/TR“!
`rrscmRC-E suH v .
`
`
`
`RAMSL‘flJ'
`-
`
`
`
`
` R'leATNG
`
`
`SYAGE
`ASSET/E17
`
`
`
`H141 VAC
`WJECIA AR “W
`
`
`Figure 1 - Ion Beam Etch System Diagram
`
`l-EUWfiUlEfi
`
`,
`
`
`Acmemtcfi smut - ___
`
`NDK‘E
`
`Etching Basics
`IBE is an anisotropic etching process that faithfully reproduces the mask pattern on the product, An Ion Beam
`is used to sputter etch material exposed by a mask (typically a photo resist) to obtain the desired pattern.
`Patterns are superimposed onto a substrate using thin film technology. Photo resist is spun onto the
`substrate and cured (soft bake). A Chrome on Quartz master mask is used to transfer the desired pattern
`onto the photo resist layer. For a negative mask resist. an Ultra Violet (UV) lamp source photo-polymerizes
`[2] the photo resist areas exposed by the master mask. After exposure. the un-exposed photo resist is
`washed away with a developer solution. A positive mask exposure is the inverse process where the UV
`exposed photo resist (poly-imid) is developed and washed away. Once the excess resist has been washed
`away, the substrate is cured in an oven (hard bake) and then mounted onto a fixture for Ion Milling. This
`process is illustrated in Figure 2.
`
`

`

`Ion Beam Etch Technology
`
`
`1. POSITIVE PHOTO RESIST EXPOSURE
`. POSITIVE PHOTO RESIST DEVELOP
`
`. ION BEAM ETCH
`
`MASTER MASK
`PHOTO RESiST
`SUSSTRATE
`
`PHOTO RESIST
`
`PHOTO RESIST
`
`SUB STRATE
`
`
`
`4. REMOVE PHOTO RESIST
`
`
`
`
`
`
`iii] mm”
`Figure 2 - Photolithography
`Ions that impact the exposed material with sufficient energy will dislodge atoms or molecules. The number of
`atoms etched by each ion is referred to as the "Sputter Yield" [1]. This process also generates significant
`heat. Cooling is required to insure that the substrate temperature does not exceed 100 degrees Centigrade.
`Excessive heat beyond 100 degrees Centigrade can distort the photoresist and ultimately impact the quality
`of the etched pattern.
`A typical etch rate for Gold is 1,200 Angstroms/minute (or 0.12 microns/minute) and 200 Angstroms/minute
`for photo resist (@ Vbeam = 500 eV and j = t mA/cm2 [1]). The etch rate for the photo resist is significant.
`Parameters such as etch depth. etch angle and aspect ratio, dictate the photo resist thickness requirement.
`The photo resist thickness has physical limitations by the application process (viscosity and photo resister
`spinner RPM). In some applications, multiple iterations of applying the photo resist pattern and etching may
`be required to achieve the desired depth. At least two datum points are required to align the mask when
`multiple photo resist applications are required to maintain pattern integrity. Side-wall redeposition and
`trenching can be significant for a large aspect ratio (feature depth/width) greater than 2 [1]. The beam angle
`of incidence cart be adjusted to remove material that has re-deposited to the sidewall. However, it is
`important to note that this method of removing side-wall redeposition has diminishing return as the aspect
`ratio increases.
`
`The ion Beam is not a significant error contributor to the patterns etched into the substrate. Significant
`pattern error contributors or variations include:
`Facets or rounding of Photo Resist
`Photo resist side-wall with positive slope Instead of vertical slope
`Photo resist shrinkage caused by improper developing and curing
`Glass mask variations
`
`Applications
`Traditionally, ion beam etching has been applied to higher value added devices, which require long
`operational lifetimes as well as precise performance specifications. These devices include commercial disk
`drive products, military and commercial communication components, microelectronic circuits and sensor
`products for automotive, medical and aerospace applications.
`Communications & Microwave Components
`Wsible signs of how micro-technology has influenced our lives is evident in how fast the cellular phone has
`transformed from a simple bulky phone to a multi-function business telecommunication hub. Today cellular
`phones are only fractions of their original size in comparison to the first units released into the market. Not
`only have they become smaller, they now offer paging, email, phone service and integrated portable
`computers all in one package.
`This level of micro-miniaturization was realized by the application of microetching and micro-machining
`techniques, such as ion beam etching. Ion beam milling has influenced the development of precise and
`compact components such as the microwave and micrdcircuitry shown in Figure 3.
`
`
`
`Figure 3 - Microwave Circuit (Neuman SEM)
`Biomedical Components 8. Sensors
`As a result of the application of ion beam etching and other micro-machining technologies, a host of new
`miniature disposable biomedical products have entered the mainstream medical market. Many of these new
`biomedical devices are based on thin film metals, polymer. glass and silicon microstructures that are
`embedded into different assemblies. Examples of these microstructures include electrodes, micro—circuits,
`nozzles, micro-channels, wells, slots. and arrays of pillar-type structures.
`Diagnostic applications utilize both passive and active devices. Passive devices take advantage of physical
`laws such as capillary flow to transport fluid samples from small wells to a series of pillars or channels that
`are coated with a reagent that reacts to the fluid. These types of stniclures are commonly found on
`pregnancy and drug detection kits where specialized reagents are used to detect specific drugs in a blood or
`urine sample. Active devices incorporate both passive and active elements. Active elements are structures
`that incorporate electrical elements such as micro-circuitry and electrodes. These active devices incorporated
`with passive elements may form pumping systems, electrode fields as well as capacitive and resistive arrays.
`See figure 4 of a microsensor array circuit,
`
`

`

`Ion Beam Etch Technology
`
`mum:
`
`r
`
`Figure 4 - 30 Circuit (Neuman SEM)
`
`Fiber Optic Components
`Fiber optics will play a key role in the way data is transmitted to and from the office, home and across the
`world. Major advances in packaging technology have made the installation of fiber networks common in
`corporations and for transporting large volumes of phone and other telecommunications across oceans.
`The most exciting of these developments is the development of Hybrid Optical Chips (HOC), Using a variety
`of microelectronic fabrication and packaging technologies, fiber optic transmit and receive modules have
`been reduced down to a level where they can be easily installed in standard PC racks.
`The next step in the evolution of these fiber optic devices is controlling the cost of fabrication Current
`methods use standard printed circuit boards and semi-precise molded fiber connectors. These devices have
`brought the retail price down to the $250 to $400 unit cost. The goal is to break the $200 mark.
`Manufacturers targeting the fiber optics communication industry see micro—technology as the solution to
`reducing costs. Development of ion etched v-grooves in silicon as well as control circuitry for the diode lasers
`has provided a rapid method of alignment for single mode and multi<mode fibers. See figure 5, By making the
`alignment of fiber to diode lasers simple as well as fast, the resulting costs are significantly reduced. The
`biggest benefit is the ability to use standard batch ion etching techniques to precisely fabricate the devices.
`By integrating, control electronics, circuitry. diode laser and fiber alignment, one can see a process where
`high-speed manufacturing can take place. This is how affordable devices in volume can penetrate the
`market.
`
`
`
`Figure 5 - V-Groove - (Neuman SEM)
`
`Trade-Off Decision Factors
`There are clear and distinctive advantages to ion beam etching. The most evident advantage is ultimate
`precision, which is measured as tolerance, Typically a tolerance of 0.1 to 0.3 microns is produced using ion
`beam etching, where as chemical etching has a tolerance of approximately 1.5 to 2.5 micron depending on
`the material and the etchant being used. Another advantage is material selectivity. In most cases chemical
`etching is limited to mostly metals, where ion beam etching can cover a wider array of material, including a
`number of organic and inorganic thin films that can not be etched by chemicals. This provides a designer with
`more freedom to use less expensive or better performing materials.
`These are the simple tradeoffs, but ultimately the bottom line plays a role in the decision process. Clearly,
`analysis needs to be done to establish the baseline cost differential between the wet and dry etch process
`technologies. Customer requirements for high density, high precision, high performance as well as low cost
`will ultimately drive the use of ion beam technology. The reason is simple, micro—miniaturization demands the
`precision of ion beam technology where chemical etching is a gamble.
`Conclusion
`ion beam etching is clearly an enabling process technology for precision micro devices and microcircuitry.
`As demands for higher density continue, ion beam etching will be the best option for offering quick and
`reliable prototyping solutions as well as batch production. The trend is evident, high-density packaging is
`here, ion beam etching provides the solution.
`References
`
`[1] Puckett/Michel/Hughes, "Ion Beam Etching", Commonwealth Scientific Corporation, Alexandria,
`VA 1991 back to article
`
`[2] Todd Lizotte and Terence O'Keefe, "lnieI/egent M/cmFab/i'calion Solutions". Jobshop Magazine
`Pages 14-18, 1994 back to article
`[3] Todd Lizotte, ”Micro Molding for Medical Applications”, Prototyping Technology International,
`Pages 1721,1997
`
`

`

`Ion Beam Etch Technology
`
`[5] John Elders and Steve Walsh, "The Micmsystem Technology Raadmap", MST Magazine. Pages
`20-22. December 1998
`[G] Janusz Brysek, etlal. "Silicon Sensors And Microstructures". Lucas NovaSensor. California. 1990
`
`Authors
`Wayne M. Stauss is the president and director of engineering for MicroFab, Mr. Stauss is responsible for
`application development. process development and vacuum tooling, MSEE 1997 and BSEE 1983 UMASS
`Lowell.
`
`Todd E. Lizotte (BSME) is the Managing Director of NanoVia a micro-fabrication process development firm,
`Mr, Lizotte is involved in MEMS & MEMS process development, with concentration in micro tluidics.
`hydrodynamic bearings. fluid/inkjet and advanced drug delivery technology.
`
`Microfab, Incl - 180 Zachary Road ~ Manchester. NH 03109 - Ph: 6036213522 ~ Fx: 603.621.9524 - info@MicroFabNH.com
`
`website designed and developed by Peregrine Design LLC
`
`