High-aspect-ratio etching

At an aspect ratio of 100:1, the flux of reactive species reaching the bottom of a trench falls to just 1.3% of what enters at the top. Etching a hole that deep and that narrow, straight-walled, without the profile tapering or bowing, is one of the defining problems of modern chipmaking — and India cannot yet do it at production scale.

High-aspect-ratio etching creates deep, narrow features with aspect ratios beyond 10:1, reaching past 100:1 in the most advanced applications. It is a gating process: in memory manufacturing, high-aspect-ratio contact etching directly determines how densely a device can be packed, and it is essential for 3D NAND and advanced logic. The physics fights back as features deepen — aspect-ratio-dependent etching slows the rate the further down you go — which is why the field is moving towards atomic layer etching, using self-limiting half-reactions to control profiles at extreme depths. AMEC in China completed strategic financing in May 2025 to accelerate ALE systems for sub-3nm logic.

As of 2026, India imports 100% of its DRIE and RIE equipment. There is no indigenous capability to design, manufacture, or deploy high-aspect-ratio etching tools. The National Nano Fabrication Centre at IISc Bangalore runs an SPTS LPX Pegasus DRIE system and Oxford Instruments RIE tools — all imported, for research. DRDO has announced indigenous 4-inch silicon carbide wafers and gallium nitride HEMTs, but no etching-process capability. Bharat Forge is making parts for lithography machines, not etch equipment.

The market shows why the gap persists. Applied Materials, Lam Research, and Tokyo Electron together held roughly 75% of global etch equipment revenue in 2025; Lam alone controls over half the dry etch market. Only six nations possess the capability. Even China's NAURA and AMEC, having built domestic dry etch tools, remain limited to nodes of 14 nanometres and above because of RF-generator licensing barriers. The tool is not a single machine but a stack of hard sub-capabilities: high-density plasma reactors, RF generators with impedance matching, vacuum and cryogenic systems holding pressure within ±2 mTorr, fluorine and chlorine etch chemistries, and real-time profile metrology. India's foundations in several of these are competitive; ALE process development is only emerging.

What it would take is legible from that list. The component capabilities exist in fragments; the missing piece is integrated process development — turning plasma chambers, RF systems, and etch chemistries into a qualified tool. India's semiconductor programmes have prioritised design IP and packaging; etch-process capability is not yet a named, funded line.