Making Tiny Chip Patterns with Special Metal-Filled Ink

This patent describes a new light-sensitive material, called a resist, that uses special multi-metal complexes to create incredibly small patterns on computer chips using extreme ultraviolet light.

What it covers

The patent outlines a method for creating microscopic patterns on a substrate, which is the base material for computer chips. First, a resist layer is formed over the substrate (Claim 1). This resist layer is unique because it contains 'metal-containing nanoparticles' that are specifically 'multi-metal complexes.' These complexes have an 'extreme ultraviolet (EUV) absorption element' (like antimony, Claim 5) and a 'bridging element' (like ruthenium, Claim 5) that connects different metal atoms. When EUV light hits the resist, a chemical change occurs: a 'first ligand' (a molecule attached to the metal complex) that couldn't connect with other complexes is replaced by a 'second ligand' that *can* participate in a 'cross-linking reaction' (Claim 1). This cross-linking process makes the exposed areas of the resist harder. Finally, a development process washes away the unexposed, softer parts, leaving behind a precise, patterned resist layer (Claim 1). For example, this process could be used to define the incredibly fine circuit lines for the transistors in a smartphone processor.

What it doesn't cover

• —Resist materials that do not contain multi-metal complexes, as the claims specifically require a 'multi-metal complex' (Claim 1).
• —Methods that use light sources other than extreme ultraviolet (EUV) for exposure, as the resist includes an 'EUV absorption element' (Claim 1).
• —Resist materials where the metal atoms within the complex are not separated by at least one ligand (Claim 1 specifies 'each metal atom... separated... by at least one ligand').
• —Processes where the exposure does not cause a ligand replacement that enables cross-linking (Claim 1 details 'first ligand... replaced by a second ligand... configured to participate in the cross-linking reaction').
• —Resist materials that are chemically amplified resists (CARs), as the patent specifically mentions a 'non-chemically amplified resist (non-CAR) layer' in some embodiments (Claim 12).

The clever bit

The novelty lies in using a specific multi-metal complex within the resist. This complex has distinct elements for absorbing EUV light and for bridging, along with a clever mechanism where EUV exposure triggers a ligand swap, directly enabling cross-linking. This allows for very precise patterning without needing additional chemical amplification.

Why it matters

This patent is crucial for the ongoing advancement of semiconductor manufacturing. Extreme Ultraviolet (EUV) lithography is the leading technology for creating the smallest features on advanced microchips, enabling more powerful and energy-efficient devices. Developing better resist materials, like the one described, is essential for pushing the limits of EUV technology, allowing chipmakers to continue shrinking transistors and improving performance. Without such innovations in materials, the progress of Moore's Law, which predicts the doubling of transistors on a chip every two years, would slow down significantly.

Real-world examples

• 1.Manufacturing of advanced logic chips (CPUs, GPUs)
• 2.Production of high-density memory chips (DRAM, NAND)
• 3.Fabrication of components for 5G telecommunications
• 4.Next-generation smartphone processors
• 5.High-performance computing components