Our key technologies leverage our expertise in producing hexafluoroisopropyl (HFIP) derivatives, which have been demonstrated to provide unique value to the semiconductor fabrication industry.
The Advantages of Hexafluoroisopropyl Chemistry
The Transparency of Fluorinated Materials to 193 and 157 nm Light:
In order to keep pace with Moore’s Law, and to achieve better resolutions in photolithography, the chip manufacturing industry has employed lasers of progressively shorter wavelengths of light. This trend has required the industry to adopt new physical and consumable technologies. The transition from 248 nm lithography to 193 nm, and then again at 157 nm posed such challenge, requiring not only investments in new laser technologies, but also the type of polymers used in compatible photoresist coatings. The constituent materials of the 248 nm photoresist coatings were not transparent to the lower wavelengths of light, rendering them unusable in the new lithographic methods. Fluorinated materials are inherently transparent at 193 and 157 nm, making them ideally suited for use in the monomers and monomer precursors of modern photoresist coatings. Halocarbon provides a broad range of customizable monomers and monomer precursors with exceptional optical transparency at lower wavelengths of light.
The Benefit of High Water Contact Angles:
In order to increase the resolution of the laser beam used in the creation of smaller and smaller feature sizes, some chip manufacturers have begun to employ immersion lithography. This technique involves replacing the air gap between the final lens element and the photoresist layer with a liquid that has a refractive index greater than that of air (>1.0). The most commonly used liquid used in this technique is water (refractive index ~ 1.3). However, this improvement bares some degree of risk, as the physical and chemical interactions occurring between water and the photoresist can lead to defects in patterning. For example, the photoresist layer can absorb water, leading to swelling and/or deleterious transmission and absorption of the impinging light. To abate the ingress of water into the photoresist, some chip manufacturers have employed the use of a hydrophobic topcoat or sought to improve the hydrophobicity of the photoresist coating itself. Halocarbon manufactures novel high-quality, high-purity HFIP-based monomers (and monomer precursors) that can provide very high water contact angles (a measure of hydrophobicity). These materials when incorporated into photoresists and top-coats have been demonstrated to provide superior hydrophobicity and exceptional patterning control.
The History of Development Solvents and The Benefits of HFIP-based Materials:
The HFIP based monomers and monomer precursors developed and manufactured by Halocarbon allow for control over hydrophobicity and hydrophilicity. A key part in the photolithography process is the clean removal of the photoresist layer from the surface of a patterned wafer. This stage of the process, known in the industry as the development step, involves the dissolution of the unpatterned portions of the photoresist using aqueous base (most commonly tetramethylammonium hydroxide, or TMAH). The acidity of the alcohol group in HFIP-based materials can be used to modulate the overall solubility of the photoresist layer at different pHs of aqueous alkalinity. This pH-triggered solubility switching allows a photoresist layer to function as a hydrophobic coating within an acidic to neutral pH-range, and as a hydrophilic and aqueous-soluble material at the alkaline pH-range, ensuring high-fidelity across both the patterning and development stages of the photolithography process.