Lithography for AI Engineers¶

A bilingual cheat-sheet that maps computational-lithography terminology onto the AI / deep-learning vocabulary you already know. Each entry has the standard definition, the closest AI analogue, a canonical reference, and a one-line Chinese summary so you can use it in either community.

写给 AI 工程师的计算光刻术语对照表 — 每条都给出英文定义、AI 类比、参考文献，外加一句中文注释，方便跨语境讨论。

Mask¶

Definition. The patterned reticle whose transmission profile is projected through the scanner onto the wafer. Digitally, a binary or grayscale 2-D image at sub-nanometer pixel pitch.

AI analogue. Input image / output tensor of an image-to-image network. A "predicted mask" is the network's output; a "target mask" is the design intent (label).

Reference. Wong, Resolution Enhancement Techniques in Optical Lithography, SPIE Press.

中文. 掩膜 — 在 AI 视角下就是一张二维图像张量；模型预测它，设计层提供监督。

OPC (Optical Proximity Correction)¶

Definition. Pre-distorting the mask so that, after projection through a diffraction-limited lens and resist development, the printed wafer pattern matches the design. Industrially solved by rule-based or model-based iterative correction.

AI analogue. Image-to-image inverse generation. Given the desired output (design), produce the input (mask) such that a known forward operator maps mask → design. A discriminative U-Net trained on (design, mask) pairs is the simplest learned variant.

Reference. Yang et al., GAN-OPC, DAC 2018.

中文. 光学邻近校正 — 类似图像逆问题：已知期望输出，反推输入。

ILT (Inverse Lithography Technology)¶

Definition. Frame OPC as a continuous optimization: parametrize the mask, define a differentiable forward model (mask → aerial image → resist), and minimize a loss against the target design.

AI analogue. Differentiable optimization with a physics-based loss — the same shape as score-matching or PINNs. Curvilinear ILT closely mirrors learned image priors regularized by a physics simulator.

Reference. Pang et al., Inverse Lithography Technology Principles in Practice, JM3 2021.

中文. 逆向光刻 — 把 OPC 写成可微优化问题，物理仿真器作为可微 loss。

SRAF (Sub-Resolution Assist Feature)¶

Definition. Small auxiliary mask features placed near main features to improve process window. They print sub-resolution (i.e., do not appear on the wafer) but bias the local diffraction pattern.

AI analogue. Auxiliary input/output channels — tokens that are part of the prediction but not part of the evaluation target. Conceptually similar to side outputs / deep supervision in segmentation networks.

Reference. Liebmann et al., SPIE Advanced Lithography, 2003.

中文. 辅助特征 — 不直接成像但影响主特征的"辅助通道"。

EPE (Edge Placement Error)¶

Definition. Distance, in nanometers, between the predicted contour and the target contour at sampled edge points. The single most important per-feature accuracy metric.

AI analogue. Edge-aligned regression loss / pixel-wise distance metric. Closer to chamfer distance than to L2 — only edge pixels contribute, and the metric is asymmetric in some formulations.

Reference. Mack, Fundamental Principles of Optical Lithography, Wiley.

中文. 边缘放置误差 — 你可以把它当作 chamfer distance 的工业版。

MRC / DRC (Mask / Design Rule Check)¶

Definition. Hard-fail compliance gating: minimum width, minimum spacing, minimum area, minimum curvature radius. A mask that fails MRC cannot be manufactured regardless of optical performance.

AI analogue. Constraint satisfaction layer — a post-hoc validity filter, similar to projection back onto a feasible set in constrained optimization.

Reference. SEMI P39, EasyMRC docs.

中文. 掩膜 / 设计规则检查 — 硬约束，类似可行域投影；不满足直接拒绝。

Resist Model¶

Definition. Model that maps the aerial image (light intensity at the wafer) to the developed resist contour. Industrial models are calibrated empirically; learned variants substitute a CNN.

AI analogue. Forward surrogate model — the SciML pattern of replacing a PDE solver with a neural network. The "true" forward model is computationally expensive; the surrogate is cheap and differentiable.

Reference. Mack, Fundamental Principles of Optical Lithography, Ch. 11.

中文. 光刻胶模型 — 物理仿真的"代理网络"，让你能微分通过它优化掩膜。

PV-Band (Process Variation Band)¶

Definition. The envelope swept by resist contours over a dose/focus process window. Width of the band measures how stable the printed pattern is under realistic manufacturing variation.

AI analogue. Aleatoric uncertainty band — analogous to a confidence interval predicted by a probabilistic model under input perturbation.

Reference. Sturtevant et al., SPIE Advanced Lithography, 2010.

中文. 工艺变动带 — 对应贝叶斯模型中的不确定性区间。

Aerial Image¶

Definition. Light intensity distribution at the wafer plane after the projection optics, before the resist responds. Computed via Hopkins / Abbe imaging from the mask plus illumination + lens kernel.

AI analogue. Intermediate latent representation — the activation in the middle of a forward pipeline. Many learned ILT models predict the aerial image as a byproduct.

Reference. Hopkins, Proc. R. Soc. A (1953).

中文. 空间像 — 光在晶圆平面的强度分布，在管线里相当于"中间层激活"。

Hotspot Detection¶

Definition. Identify layout patches that are likely to fail under nominal lithography conditions (bridge, break, necking). Trained on (layout patch, hotspot label) pairs from prior tape-outs.

AI analogue. Pixel-level or patch-level anomaly classification — same task structure as defect inspection, semantic segmentation of defects, or out-of-distribution detection.

Reference. Yang et al., DAC 2017 / Lin et al., ICCAD 2016.

中文. 热点检测 — 标准的分块分类 / 语义分割问题，标签来自历史 tape-out 数据。

Stochastic Failure (EUV-specific)¶

Definition. EUV photons arrive Poisson-distributed; resist response is also stochastic. Below a critical dose, low-photon variance produces random bridges, breaks, and missing contacts.

AI analogue. Monte Carlo sampling under input noise — similar to evaluating a model's robustness to per-pixel Gaussian perturbation, but the noise here is physically grounded photon shot noise.

Reference. De Bisschop, J. Micro/Nanolith. MEMS MOEMS, 2017.

中文. EUV 随机失效 — 光子打靶的统计性涨落，可用蒙特卡洛仿真评估。

Process Window¶

Definition. The set of (dose, focus) pairs over which all CD/EPE/MRC constraints are simultaneously satisfied. A wider window means the recipe is more robust to scanner drift.

AI analogue. Feasible region in the input-perturbation parameter space — analogous to the set of latent perturbations that preserve a classifier's decision.

Reference. Sturtevant et al., SPIE Advanced Lithography, 2010.

中文. 工艺窗口 — 各类约束同时满足的 (dose, focus) 集合，类似分类器的稳健决策区域。