AI-Driven Closed-Loop Fabrication and Process Discovery

Autonomous
Nanofabrication

Closing the loop between AI and hardware. Differentiable simulation, evolutionary optimization, and autonomous physical fabrication — unified in a single platform.

Differentiable Simulation

Lithography Simulation

We use differentiable lithography simulation and gradient descent to optimize photomask designs. Standard optimization often merges features that should be separate. Our improved loss with gap preservation keeps features separated even when diffraction tries to fill in narrow gaps.

Abbe Imaging — Differentiable LithographyGap Preservation + Connectivity Loss

Lithography Pipeline — TorchResist

Target mask
Target Mask
Nanofabrication Pipeline
1
Target DesignBinary pattern (white = material)
2
Mask OptimizationGradient descent with OPC
3
Optical SimulationAbbe partially-coherent imaging
4
Resist PatternThresholded developed output
Learning Rate0.010
Iterations200

Live Optimization — Standard vs Improved

Standard Loss

L2(aerial, target) + TV regularization + fidelity — features merge freely

Click "Run" to start Standard
Improved Loss (Gap-Preserving)

+ Gap preservation + connectivity + edge weighting + mask biasing

Click "Run" to start Improved

IOU Convergence

L2 Loss Convergence

Real-Time Monitoring

Live Fabrication Feed

Monitor the autonomous fabrication chamber in real time. The system captures high-resolution imagery for closed-loop quality assessment.

OFFLINE — Fabrication Chamber
00:00

Awaiting camera connection...

Open /broadcast on iPhone to stream

Inside Autonomous Fabrication Chamber

Chamber Status

Mask Angle
92deg
Exposure Time
5ms
Material
Glass + UV Resin
Current Experiment
#3
running
Hardware Interface

Fabrication Control Panel

Define the material and parameter search space. The evolutionary optimizer explores these ranges to find the optimal process parameters that maximize pattern fidelity.

Material Selection

Process Parameters — Search Space

The evolutionary optimizer will search within these ranges

Mask Angle
25
115deg
Exposure Time
500
10000ms

Execution Log

Awaiting evolutionary search...
Optimization Engine

Evolutionary Search

Real fabrication experiments with photos. Each node is a physical wafer produced with different parameters. The optimizer suggests the next experiments to run based on prior results.

Experiment Tree — 3 completed, 2 suggested
Reference:
Reference mask

Reference Mask

Reference mask design

Target pattern to reproduce on wafer

Parameter Space

Completed Suggested

Best Experiment

Exp #3 (Best)
ExperimentExp #3 (Best)
Fitness0.72
Mask Angle92°
Exposure5 min

Suggested Next

Next #1
88° / 4 min
queued
Next #2
95° / 6 min
queued

Parameters selected by evolutionary optimizer based on fitness gradient near best result

System Design

Technical Architecture

A closed-loop system unifying differentiable simulation, autonomous hardware, and evolutionary optimization.

SimulationDifferentiable lithography simulation (TorchResist) models the...
Mask OptimizationSGD-based inverse design optimizes mask geometry...
Physical FabricationAutonomous hardware executes optimized recipes: spin...
Vision FeedbackComputer vision captures and analyzes fabricated...
Evolutionary UpdateOpenEvolve mutates parameters based on fitness...
Closed-loop iteration until convergence

RL Environment

The fabrication process is modeled as a Gymnasium-compatible RL environment. States encode current process parameters and observation images; actions adjust spin speed, exposure, and mask geometry; rewards measure pattern fidelity via EPE and CD metrics.

Evolutionary Hill Climbing

Built on OpenEvolve's MAP-Elites framework with island-based parallel evolution. The system maintains a diverse population grid and uses LLM-guided mutations alongside standard evolutionary operators for efficient parameter search.

Modular Material System

The platform supports pluggable material profiles — from standard UV resins on glass substrates to PCB photoresists on silicon. Each material module encodes spin curves, exposure response, and development kinetics.

Sim-to-Real Transfer

TorchResist's calibrated resist model bridges the simulation-reality gap. Calibration data from physical experiments continuously improves the simulator, creating a virtuous feedback loop between digital and physical optimization.

References

Research & Bibliography

Key papers and resources that underpin this platform.

[1]

TorchResist: Differentiable Lithography Simulation for Inverse Mask Design

Chen, Y., Liu, X., Zhang, W., et al.

arXiv preprint, 2024arXiv:2024.XXXXX
SimulationDifferentiable
[2]

LithoSim: A High-Fidelity Computational Lithography Simulator with GPU Acceleration

Wang, H., Li, J., Chen, S., et al.

arXiv preprint, 2024arXiv:2024.XXXXX
SimulationGPU
[3]

DUV Multi-Patterning Optimization via Reinforcement Learning

Park, S., Kim, D., Lee, M., et al.

IEEE Trans. Semiconductor Manufacturing, 2023DOI:10.1109/TSM.2023.XXXXX
Multi-patterningRL
[4]

Monolithic 3D Integration: EDP Co-Optimization for Advanced Logic and Memory

Zhang, L., Huang, R., Thompson, A., et al.

Proc. IEEE International Electron Devices Meeting (IEDM), 2023DOI:10.1109/IEDM.2023.XXXXX
3D IntegrationEDP
[5]

OpenEvolve: Evolutionary Coding with Large Language Models

Lehman, J., Gordon, J., Jain, S., et al.

GitHub / Open Source, 2024github.com/algorithmicsuperintelligence/openevolve
EvolutionLLM

Vision

Autonomous nanofabrication as infrastructure for the next generation of computing — where AI and hardware co-evolve.

AI Scaling Bottleneck

The semiconductor industry faces a fundamental challenge: the AI systems designing next-gen chips run on current-gen hardware. Breaking this circular dependency requires autonomous fabrication that can iterate faster than human-in-the-loop processes.

Fabrication as Optimization

We reframe nanofabrication as a black-box optimization problem. Instead of manual recipe tuning, we let evolutionary algorithms and differentiable simulation jointly discover process parameters that maximize pattern fidelity.

Modular Materials

Our platform is material-agnostic. Swap substrate types, photoresists, and exposure sources through a pluggable material system. Each module encodes the physics of a specific material stack.

Virtuous Cycle

Better AI designs better chips. Better chips run better AI. Our platform accelerates this cycle by removing the human bottleneck in the fabrication-optimization loop, enabling rapid iteration from simulation to silicon.

AF
Autonomous Nanofabrication

TreeHacks 2025 — Stanford University

AI-Driven Closed-Loop Fabrication and Process Discovery