Leading Semiconductor Miniaturization: Metal Hard Mask (MHM) Deposition Technology
ULVAC supports the manufacturing of cutting-edge devices through deposition technologies that enable semiconductor miniaturization. Among these, Metal Hard Mask (MHM) deposition technology plays a crucial role as a key solution for advanced processes that realize finer circuit patterns.
What is MHM?
A Technology Enabling Ultra-Fine Circuit Formation MHM refers to a specialized metal film used as a "hard mask" to precisely form intricate circuits during the semiconductor manufacturing process. In semiconductor fabrication, "patterning"--the process of transferring circuit designs onto silicon wafers--is a critical step. This process is similar to using a sophisticated "template" to carve complex grooves into a board. In conventional processes, the "photoresist" (a light-sensitive resin) was used directly as the template for etching. However, as miniaturization requires deeper and sharper etching, resin-based resists often lack the etch resistance to withstand the increased load, resulting in template erosion or pattern distortion. To address this, a robust metal film is deposited beneath the photoresist--this is the MHM. First, the resist acts as a temporary template to pattern the metal film; then, this strong metal layer serves as the final hard mask for the main etching process. By using metal, which is much harder than resin, it becomes possible to etch ultra-fine circuits with high precision. ULVAC's expertise in MHM technology is a core strength supporting advanced semiconductor manufacturing.
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ULVAC's Strength: Proprietary Film Stress Control Technology
The material used for MHM is high-hardness TiN (titanium nitride). Traditionally, depositing films under conditions that maintain high density resulted only in films with strong "compressive stress" (the tendency to shrink inward). Since excessive stress can cause wafer warpage or the collapse of fine patterns, precise stress control during the deposition process is essential. In response to customer requests for more stable device manufacturing, ULVAC developed a TiN film that maintains high density while exhibiting "tensile stress" (the tendency to expand outward). By repeatedly optimizing equipment design and process parameters, ULVAC achieved nano-level control of TiN crystal orientation, establishing proprietary technology to freely control film stress without sacrificing density. This advanced capability to "control film properties as intended" is the main reason ULVAC is chosen by global leaders.
Future Outlook: A Core Technology Supporting Semiconductor Growth
Since its introduction, MHM deposition technology has become a core technology driving the growth of ULVAC's semiconductor business. Today, the application of MHM technology is expanding beyond the logic sector requiring EUV lithography to a wide range of new device fields. ULVAC will continue to steadily address the technical challenges presented by our customers. Through innovative deposition solutions and reliable technological excellence, we will continue to contribute to the advancement of the global semiconductor industry.