Understand CoWoS, HBM, and FOWLP: A Beginner-Friendly Semiconductor Keyword Map

In the semiconductor value chain, from lithography and transistor design to packaging and stacking, each term represents a key technology and market opportunity. Have you seen terms like CoWoS, HBM, Chiplet, TSV, or GAAFET in tech news but felt lost? This guide summarizes the most important and trending semiconductor keywords in a way that's easy to understand for investors and tech enthusiasts.

Upstream Technologies: Materials and Lithography

At the beginning of semiconductor production, materials and lithography define the resolution and precision of the entire chip-making process. With process nodes now pushing below 5nm, EUV lithography has become a decisive technology in leading-edge manufacturing.

🔹 EUV (Extreme Ultraviolet Lithography)

EUV uses extremely short light waves (13.5 nm) to etch ultra-fine patterns onto silicon wafers, enabling advanced nodes like 5nm, 3nm, and 2nm. It's the most advanced lithography technology currently in mass production.

Example: Like writing calligraphy on a grain of rice — without EUV, TSMC’s 3nm process wouldn’t exist.

🔹 DUV (Deep Ultraviolet Lithography)

DUV uses longer wavelengths (193nm) and was the standard before EUV. It remains widely used for mature processes.

Example: Like an old-school master craftsman—reliable, precise, and still essential.

🔹 Reticle (Photomask)

A reticle is the stencil used to project circuit patterns onto the wafer. It determines the precision of the lithography.

Example: Think of it as the mold used for shaping takoyaki — precision starts here.

🔹 InFO (Integrated Fan-Out)

TSMC’s fan-out packaging that skips traditional substrates. Chips are embedded directly into the RDL (Redistribution Layer), allowing slimmer devices and better thermal performance. Used in Apple A-series chips.

Example: Like reorganizing the internals of a phone so everything fits tightly and performs better.

🔹 3D IC (3D Integrated Circuit)

A vertical stacking technique that connects multiple chips using TSVs (Through-Silicon Vias). Ideal for AI and HPC.

Example: Like stacking floors in a skyscraper instead of building outward — saves space and speeds communication.

Midstream Technologies: Transistor & Process Engineering

Transistor architecture and power routing define the core performance of chips. In this phase, we encounter FinFET, GAAFET, and BSP — foundational technologies enabling modern CPUs and AI chips.

🔹 FinFET (Fin Field-Effect Transistor)

A 3D transistor with fin-like channels that offer better control and reduce leakage current. Used from 22nm down to 5nm.

Example: Like standing up a pipe to get faster water flow — FinFET revolutionized chip efficiency.

🔹 GAAFET (Gate-All-Around FET)

A next-gen transistor that surrounds the channel on all sides, improving control and performance at nodes below 3nm.

Example: Like wrapping a pipe completely to prevent any leakage — ultimate control.

🔹 BSP (Backside Power Delivery)

Moves power routing from the chip’s front side to the back, reducing resistance and freeing up space for signal routing. Key to 2nm and beyond.

Example: Like adding a second expressway just for electricity — improves speed and efficiency.

Downstream Technologies: Packaging & Integration

Modern packaging is more than chip protection — it’s the battleground for performance. With AI and HPC growing fast, terms like CoWoS, HBM, and Chiplet dominate the conversation.

🔹 CoWoS (Chip-on-Wafer-on-Substrate)

TSMC’s 2.5D packaging platform that combines logic and memory chips (like HBM) onto an interposer with TSV interconnects.

Example: Like mounting several supercars onto one warship and launching together. NVIDIA H100 uses this tech.

🔹 HBM (High Bandwidth Memory)

Stacked DRAM connected via TSVs to enable high-speed data access with low power — essential for AI training and graphics.

Example: Like placing a memory warehouse right next to the processor.

🔹 FOWLP (Fan-Out Wafer-Level Packaging)

Enhances chip I/O and thermal efficiency by extending the chip's wiring outside its original footprint using RDL.

Example: Like giving your phone multiple robotic arms — faster and cooler.

🔹 Chiplet

Breaks down a large chip into functional modules. Each Chiplet can be manufactured independently and later integrated via advanced packaging.

Example: Like building a supercomputer out of LEGO bricks.

🔹 SoIC (System on Integrated Chips)

TSMC’s 3D packaging stack using direct die-to-die bonding for ultra-low latency and compact form factors.

Example: Like stacking CPU, GPU, and memory into one sandwich.

🔹 FiNet

TSMC’s internal high-speed interconnect solution between Chiplets and other stacked modules.

Example: Think of it as an internal fiber-optic network for your chip.

🔹 TSV (Through-Silicon Via)

Vertical vias that connect stacked chips in 3D ICs, reducing latency and power consumption.

Example: Like an elevator in a skyscraper connecting all floors instantly.

🔹 RDL (Redistribution Layer)

A wiring layer used in packaging to rearrange I/O pads for better routing flexibility.

Example: Like rerouting outlets in your home for convenience.

🔹 2.5D IC

Uses an interposer to integrate multiple chips side-by-side with high-speed connections. Ideal for AI & HPC.

Example: Like open office seating — everyone’s connected but in their own space.

(Continue with glossary table, system architecture section, advanced memory trends, and CTA...)

System Architecture & Integration Technologies

🔹 EDA (Electronic Design Automation)

EDA tools are essential software used to design chips — including circuit schematics, layout, simulation, and verification. Without EDA, modern chip complexity would be impossible to handle. Key vendors include Synopsys, Cadence, and Siemens EDA.

Example: Like CAD software for architects, EDA is what enables engineers to design and validate chips.

🔹 CXL (Compute Express Link)

A high-speed interconnect standard allowing CPUs, GPUs, and accelerators to share memory. It addresses bandwidth and latency bottlenecks in AI and data center workloads.

Example: Think of CXL as the data-sharing express lane between different processing units.

🔹 RISC-V (Reduced Instruction Set Computing – V)

An open-source instruction set architecture (ISA) offering modularity, transparency, and cost efficiency. It's gaining momentum in academia, IoT, and sovereign chip initiatives.

Example: RISC-V is like open-source Lego blocks for building processors — flexible, cheap, and community-driven.

🔹 Advanced Packaging

A broad term encompassing 2.5D, 3D IC, Chiplet, CoWoS, and SoIC. As Moore’s Law slows, performance improvements shift to how chips are assembled and interconnected.

Example: Advanced packaging is like designing a multi-core robot with modular components, where internal wiring is as important as each function.

Emerging Trends in Packaging & Memory

🔹 HBM3E (High Bandwidth Memory Gen 3E)

The enhanced version of HBM3 offering higher bandwidth (over 9 Gbps per pin) and increased stacking. It supports cutting-edge GPUs and AI training chips.

Example: Like upgrading your memory expressway with more lanes — faster AI model training.

🔹 FOCoS (Fan-Out Chip-on-Substrate)

Developed by ASE, FOCoS integrates fan-out packaging with a substrate base, offering cost-effective, high-density integration. Seen as a competitor to TSMC’s CoWoS.

Example: Like customizing a super-dense chipboard that’s cheap but still powerful.

🔹 Hybrid Bonding

A 3D IC technology bonding two dies at the metal and dielectric level (Cu-to-Cu + oxide). It enables ultra-high density, low-latency interconnects for Chiplet and memory stacks.

Example: Like gluing two chip surfaces seamlessly without bumps — enabling whisper-fast data exchange.

Semiconductor Technology Glossary Table

Technology	Description	Category
EUV	Extreme Ultraviolet Lithography	Upstream
DUV	Deep Ultraviolet Lithography	Upstream
Reticle	Photomask used in lithography	Upstream
FinFET	Fin Field-Effect Transistor	Midstream
GAAFET	Gate-All-Around FET	Midstream
BSP	Backside Power Delivery	Midstream
CoWoS	Chip-on-Wafer-on-Substrate packaging	Downstream
HBM	High Bandwidth Memory	Downstream
FOWLP	Fan-Out Wafer-Level Packaging	Downstream
Chiplet	Modular small chip components	Downstream
SoIC	System on Integrated Chips (3D stacking)	Downstream
FiNet	TSMC's interconnect for Chiplets/SoIC	Downstream
TSV	Through-Silicon Via interconnects	Downstream
RDL	Redistribution Layer for I/O	Downstream
2.5D IC	2.5D Integrated Circuit packaging	Downstream
EDA	Electronic Design Automation tools	System Architecture
CXL	Compute Express Link (high-speed interface)	System Architecture
RISC-V	Open-source processor instruction set	System Architecture
Advanced Packaging	Broad term for advanced chip packaging forms	System Architecture
HBM3E	Next-gen stacked memory (HBM3 upgrade)	Packaging & Memory Trends
FOCoS	ASE's fan-out + substrate hybrid package	Packaging & Memory Trends
Hybrid Bonding	Cu-to-Cu and oxide die bonding technique	Packaging & Memory Trends