Tunable metamaterials with carrier-induced effective permittivity for active control of electromagnetic fields in semiconductor manufacturing device

Precise control of electromagnetic fields is critical in many advanced manufacturing processes, such as those used in the semiconductor industry, where device performance relies on precision and uniformity. Varying the relative permittivity of adjacent materials effectively controls electromagnetic fields in a three-dimensional space. However, finding suitable low dielectric-loss materials with a large tunability is challenging. To overcome this, metamaterial-based approaches have been explored. While promising, further research is required to enlarge the frequency bandwidth, widen the achievable permittivity ranges, and find a simple tuning mechanism. Here, we propose a solution based on a geometrically-designable permittivity enhancement principle, free from the fundamental constraints on the frequency bandwidth and dispersion inherent in resonance-based tuning principles. We report an experimentally measured record-high broadband permittivity change over 250 %. The proposed structure includes a patterned semiconductor material that allows tuning the effective permittivity through carrier-density modulation. This carrier-responsive metamaterial (CRM) exhibits frequency-independent behavior over several decades of frequencies and a large tunability in the permittivities based on the dynamically controlled conductivity of the semiconductor region. We present an intuitive model that can explain the relationship between the CRM’s structure and properties including its effective permittivity and loss tangent. We also provide rigorous numerical simulations and experimental measurements to verify the concept. As an application, we explore CRM’s potential in plasma control, revealing its ability to influence plasma uniformity by over 10%. This research illuminates CRM’s versatile functionality and potential impact across diverse technological domains.