2.5D & 3D IC
Advanced packaging technology is a critical factor enabling dramatic improvements in device performance as well as package form and fit factors.
Thin Wafer Handling
Brewer Science® ZoneBOND® technology is the proven thin-wafer-handling technology that combines materials, processes, and equipment. The close interaction among materials, processes, and equipment requires careful and holistic tuning for each component. Until recently, many in the industry thought these to be mutually exclusive. Brewer Science’s success in temporary wafer handling arose from the company’s knowledge of this three-way interaction and the understanding of how to determine and balance these three aspects.
Brewer Science offers a broad product portfolio for advanced packaging, including:
- Chemical release technology
- Debonding Equipment
- High-temperature slide-off debonding of thinned III-V and compound semiconductor materials
- Low-stress room temperature debonding
- Thermal slide debonding technology
- A stable platform for wafer thinning and backside processing
- Excellent uniformity
- Protection from harsh process chemicals
- High throughput and yield
- ZoneBOND® technology
The ZoneBOND® low-stress debonding process detaches the carrier wafer from the laminated device wafer at room temperature using very low mechanical force for the separation. The technology utilizes two different “zones” for controlled adhesion of the device wafer to the carrier wafer. The device wafer is truly adhered to the carrier wafer only in a small area along the outer edge of the carrier wafer, while the rest of the wafer remains unbonded but completely supported.
Advantages of Brewer Science® ZoneBOND®:
- Higher yields at debonding.
- Low-stress thermal and mechanical debonding protects the fragile device wafer.
- Separation takes place between the adhesive and the carrier wafer, not the adhesive and device wafer.
- During separation, the device wafer is on film frame or other carrier, safely mounted on a vacuum chuck.
- Targeted to be much higher debonding throughput than competitive solutions.
- Higher throughput and lower cost of ownership.
The debonding process includes three major steps:
- Edge Cut: Dissolution of the adhesive in the outer zone by penetration of solvent from the edges.
- Lamination: Attachment of the bonded wafer to a film frame or other carrier.
- Separation: Peeling of the carrier wafer, using dedicated equipment, from the device wafer that is supported on a specially designed vacuum chuck.
Materials: ZoneBOND® High-temperature-tolerant materials
Equipment: ZoneBOND® separation tool
One of the unique advantages of the ZoneBOND® process is that it can be used to bring about a simple "flip" of the thin wafer to access to the wafer's front side, which is the device side, for further processing or testing. The thin wafer is supported on a carrier through the entire flipping process. The following video clip provides a step-by-step description of the patent-pending wafer flipping process.
During chemical debonding, the device wafer is debonded from the rigid carrier by immersion in solvents. This process utilizes a perforated carrier wafer that allows diffusion of solvent to the adhesive layer.
Materials: WaferBOND® CR200 Material×
Thin Wafer Handling Equipment
Brewer Science® wafer debonder product line permits debonding of processed, proprietary ultrathin wafers. Development engineers can complete the final step for thin wafer processing in a confidential environment for:
These precision tools are the bridge between low-stress room temperature debonding or thermal high temperature slide-off and thin wafer handling for low-volume prototype production. These tools, along with the Brewer Science® ZoneBOND® system for thin wafer handling, can accelerate your product development cycle and improve time to market for advanced thin wafer handling technologies.×
Thermal Slide Debonding
During slide debonding, the device wafer is debonded from the rigid carrier using a thermomechanical process. The bonded wafer is heated to a specified temperature at which the adhesive is softened, followed by mechanical sliding of the carrier from the ultrathin wafer.
Brewer Science® WaferBOND® HT materials enable the creation and backside processing of ultrathin wafers by providing:
ZoneBOND® Thin-Wafer-Handling Technology
ZoneBOND® technology is the proven thin-wafer-handling solution designed to withstand CVD and PVD backside processing, then debond with the lowest stress possible. Our approach to temporary wafer handling combines our expertise in materials, process integration, and equipment with an understanding of how to determine and measure the balancing point between these three components.
The ZoneBOND® technology offers excellent total thickness variation (TTV) control across the device wafer, high-temperature stability, and debonding under low-stress conditions to preserve thin wafer integrity. Brewer Science provides materials, technical consulting, process development consulting, equipment development consulting, and process testing for thin-wafer-handling and TSV creation.
Planarization - Trench Fill
3-D fabrication and packaging process flows may include steps that necessitate coating resists and other materials over deep and wide features such as trenches. These steps typically result in low yield and low throughput as several layers of the resist are needed to fill the trenches prior to lithography. Brewer Science offers planarization technology, including materials and processes to planarize the deep features.
Brewer Science products provide a planar surface when coated over high-aspect-ratio structures.
Trench prior to coating
Coating after develop
Backside processing steps such as etching and deposition require direct contact of front-side circuitry to the chuck in the deposition or etch chambers. The handling and chucking process can damage the fragile and expensive circuitry. Brewer Science offers scratch-resistant and spin-coatable materials for the protection of the front surface for backside processing and dicing.
Wafer-level packaging (WLP) is commonly used for packaging of MEMS and LED devices as it offers advantages in cost, yield, and reliability. In a WLP scheme, MEMS structures or LED die are encapsulated between bonded wafers, one of which has cavities that are fabricated most commonly by bulk micromachining.
Bulk micromachining is a process typically used in applications such as micromachinery or microelectromechanical systems (MEMS).
Unlike surface micromachining, which uses a succession of thin film deposition and selective etching steps, bulk micromachining defines structures by selectively etching inside a substrate. Whereas surface micromachining creates structures on top of a substrate, bulk micromachining produces structures inside a substrate.
- ProTEK® PSB - Photosensitive alkaline protective coating
- Apply an etch mask over CMOS structures due to low process temperatures
- Reduce processing time because pattern transfer by dry etch is not required as it is with silicon nitride
- Achieve higher throughput by using batch processing instead of a single-wafer DRIE process
- ProTEK® B3 coatings for alkaline etching
- Protect delicate front-side circuitry during back-side bulk micromachining
- Increase yield by minimizing front side damage caused by alkaline etch solution punch through during wet etch
- Improve throughput by reducing labor and process time associated with mechanical clamps and increasing the number of wafers per etch bath
- Protect CMOS circuitry or MEMS structures
- Create SiN membranes last
- Create through-silicon vias (TSVs)
- ProTEK® SR coating for dry etching
- Durable polymer coating protects delicate front-side circuitry during backside DRIE etching.
- High film hardness (9H pencil) resists scratching.
- High glass transition temperature (117°C) assures ProTEK® SR film will not stick to DRIE chuck.
- Low outgassing in a vacuum assures no contamination of DRIE chamber or process.
- Low film ion levels prevent contamination of wafers, tools, and handling equipment.
ProTEK® PSB Coatings Photosensitive protective coating
ProTEK® PSB coating is a spin-on replacement for Silicon Nitride or Silicon Oxide wet etch masks. When applied in combination with ProTEK® B3 coating, it offers a full solution to alkaline wet etching. It can be applied after the CMOS circuitry is created and does not require mechanical clamps for protection.
With ProTEK® PSB coating, you can:
Brewer Science® ProTEK® PSB coating is used in the creation of inverse pyramidal pits as discussed in SUN Microsystems' technical paper, "Active Demonstration of a Passively Self-Aligned, Multi-Chip Package using Proximity Communication in a Switching Fabric" presented at the 42nd Annual International Symposium on Microelectronics - IMAPS 2009, San Jose, December 1-5, 2009.
ProTEK® B3 Coatings Alkaline protective coating
ProTEK® B3 thin films are spin-applied polymeric coating systems that provide temporary wet-etch protection for CMOS MEMS circuitry during alkaline or acid etches. ProTEK® B materials offer protection from alkaline solutions such as KOH and TMAH for extended bath etches.
With ProTEK® B3, you can:
Apply ProTEK® B3 coating instead of mechanical clamps to:
ProTEK® SR Coatings Scratch-resistant coating
ProTEK® SR coating is a spin-applied polymeric coating designed to provide maximum protection for fragile, etch-sensitive circuitry placed in direct contact against the interior chuck of the etch chamber. ProTEK® SR coating offers durability and longevity against harsh backside DRIE processes typically utilized by the microelectromechanical systems (MEMS) and integrated circuit (IC) industries.
ProTEK® SR coating offers the following features: