3D-IC an Enabler Technology and a new Landscape Yves Leduc Advanced System Technology November 2009

What every Architect should know about Technology, Sani R. Nassif, IBM Research Austin. Design Variability: Challenges and Solutions at microarchitecture - architecture level DATE’08, München MANUFACTURABILITY : the ability to create PROFIT ABLE IC’s. Forewarning, our only concern:

Motivation Glossary Technology Enabled Innovations Status New Jobs

Motivations 3D-SIP 3D-STV

According to SEMATECH The advantages of 3D-TSV over the alternatives By combining the performance and power of system-on-chip (SOC) with the functionality and time-to-market advantages of system-in-package (SiP), TSV offers the best of both for achieving very high densities for memory and logic. Its advantages over SoC and SiP include: Greater density for the same footprint More functionality Higher performance Lower power consumption Lower cost More manufacturing flexibility Faster time to market

2D Span of Control n  r 2 3D Span of Control n  r 3 Larger the die, more appealing is 3D interconnect r x y r z x y

Glossary

F2F, where dies are soldered Face to Face B2F, where dies are bonded Back to Face Glossary:F2F, B2F Pads dies interface Pads dies interface Microbumps Silicon Through Vias aka STV

D2W, Die to Wafer Soldering F2F Bonding B2F W2W, Wafer to Wafer Bonding B2F Glossary:D2W, W2W

3D-IC’s F2F Multi B2F B2F WSP Compatible

One Example of 3D-IC Technology B2F, D2W

an Example from IMEC: 3D-IC [ Snapshot ] Processed wafer A, with STV Processed wafer B Temporary carrier Temporary carrier bonding Silicon of wafer A thinning Dies singulation Dies A to wafer B alignment Die bondingSuper dies singulation Carrier removal Super diesAdhesive coating Temporary adhesive coating

Super-dies are singulated  an Example from IMEC: 3D-IC Carrier

Technical Dashboard What is IMPORTANT to have? The removal of the die to die ESD protections to get the density of STV without impacting the circuit integration. Low pin count solution to make WSP possible. Thermal awareness. What will be the key ENABLER? Wafer thinning technology drives directly cost and STV densities. What -SEEM- to be the BEST technical options? B2F, as bonding should be preferred to soldering for STV densities. ? ‘Vias First’ STV brings highest density, but processed in wafer fab ? ‘Vias Last’ STV are built in assembly plant D2W or W2W: currently unclear.

Single Chips Side by Side Dies Stacked Dies F2F B2F Usage: System area System cost Performances Flexibility Heat dissipation PCB process complexity Package process complexity Risks Technology maturity WSP compatibility

Enabled Innovations

3D-IC is a technology breaking the boundaries of IC’s. It offers direct connections between modules. The super-die created by the bonding of several dies is not an assembly of dies but a true SOC with superior connections. Die 1 Die 2 Die 3 One Super-Die >1000’s connections / mm 2 3D-IC is a SOC Technology

Compared to 2D counterparts, 3D-IC SOC’s have shorter connections to many more neighbors. They offer many more connection planes and shorter paths to route signals. 3D Topology brings more Compact Architecture

There is no need to specific drivers to make die to die connections There is no need to place ESD protections on these internal connections Superior Connections without Penalty 1.2V 1.2V – 3.0V Low RLC connections No pad No ESD protection Pads ESD protections I/O’s

Massive transfer between cache memories breaks data transfer bottleneck. Tuned processes offer lower cost and better performances. Enhanced connection capability by enabling efficient NOC solutions. SRAM cache 1 DSP ARM … NOC SRAM cache 2 Embedded PM I/O’s … 1.2V Low leakage 1.2V – 3.0V 1 000’s connections Example of Enhanced Performances SOC

Example of a Flexible Platform 1 000’s connections Processors WiFi, Bluetooth, NFC.. USB, FireWire.. NOC.. Power Management.. … 1 000’s connections Memory 1.2V 1.2V – 3.0V

Enabling Application: Memory! 8 * Memory N bits = Memory N bytes 8 identical IC’s

Manufacturability  Our only concern:

According to “Today, fabs running iTSV can produce 3D-TSV devices at a total Cost of Ownership of less than $150usd per wafer. Improved synchronization between the unit processes along with aggressive cost saving designs have been very successful at exceeding the consortium’s original cost goals.” [ July 2009 ] CW = (CF+CV+CY)/(TPT*Y*U) where: CW = Cost per wafer CF = Fixed cost CV = Variable cost CY = Cost due to yield loss TPT = Throughput Y = Composite Yield U = Utilization

Samsung debuts world’s thinnest multi-die package Samsung Electronics has developed the world’s thinnest multi-die package, one that measures 0.6mm in height. Designed initially for 32 gigabyte (GB) densities, the new memory package is just half the thickness of a conventional memory package of eight stacked chips (or dies). The advanced packaging technology delivers a 40 percent thinner and lighter memory solution for high-density multimedia handsets and other mobile devices, according to the company. […] The newly developed ultra-thinning technology overcomes the conventional technology limits of a chip’s resistance to external pressure when under 30um in height. The productivity decline resulting from this thickness limitation had been directly attributable to a drop in production yields during mass production. […] The 15um-thickness represents a significant achievement as it can allow for double the density of previous multi-chip packages. The thinner die also dramatically reduces chip weight. In addition, the new package technology can be adapted to other existing MCPs, configured as system in packages (SiPs), or package on packages (PoPs). The breakthrough technique for 15um-and-under chip thicknesses will allow for the design of very high density solutions with the smallest of form factors – an extremely attractive prospect for the highly competitive mobile market. [ November 2009 ] KEY ENABLER

System [r]evolution New know-how !

The Job of IC Designers is Changing! 3D-IC is bringing many new degrees of freedom. Packaging becomes a key technology and impacts early decisions. System partitioning is more important than ever. Early analysis is essential. Analysis must be done from PCB to Silicon. Analyze systems at the highest level. Job is too serious to not involve early technical specialists. Need a Strong Expertise in System Exploration, What-If analysis: -> Process Performances Understanding and Cost evaluation -> Specification modeling and simulation -> Transaction level modeling and simulation -> High Level Mixed Signal modeling and simulation -> Heterogeneous modeling and simulation -> Thermal modeling and simulation -> Advanced Packaging …

Open for discussion !