Displays

Display technology continues to evolve rapidly, powering everything from mobile devices to high-resolution monitors and emerging flexible screens. Thin-Film Transistors (TFTs) form the backbone of modern displays, with technologies ranging from amorphous silicon to advanced oxide semiconductors like IGZO and organic materials. As pixel densities increase and new form factors emerge, developing reliable, efficient TFT structures requires sophisticated simulation capabilities that can predict device behavior across different materials, architectures, and operating conditions.

Display TFTs present unique challenges compared to conventional silicon devices, including amorphous and polycrystalline material structures, large-area fabrication requirements, and performance optimization across varying temperature and illumination conditions.

• a-Si (Amorphous Silicon) offers mature, cost-effective manufacturing for mainstream displays.
• LTPS (Low-Temperature Polysilicon) provides higher carrier mobility for high-performance displays.
• IGZO and Oxide Semiconductors deliver excellent uniformity over large areas, low off-state current, and transparency for emerging applications.
• Organic Materials enable flexible and lightweight displays with unique optical properties.

GTS Minimos-NT provides the comprehensive simulation framework needed to analyze and optimize display TFTs from device level to integrated pixel circuits.

Modern TFT designs leverage three-dimensional structures to optimize performance within area constraints. Key structural elements include:

• Gate electrode and dielectric layers
• Active semiconductor channel (a-Si, LTPS, IGZO, or organic)
• Source and drain contacts with appropriate barrier materials
• Passivation and protective layers

GTS Framework enables rapid exploration of design variants, including bottom-gated, top-gated, and double-gated configurations.

Device models can be efficiently generated based on layouts and process emulation flows yielding realistic conformal TFT topographies. Automated anisotropic mesh generation optimizes computational efficiency while maintaining accuracy in critical regions.

The workflow supports both full three-dimensional device simulation and efficient sectional approaches. Validation between 2D and 3D simulations ensures efficient analysis while maintaining predictive accuracy.

Display TFTs require specialized materials models that capture the physics of amorphous and disordered semiconductors:

Effective Mobility Modeling accurately reproduces experimental gate bias dependency of mobility over large temperature ranges. Detailed microscopic models scale to the 100 nanometer range, while efficient effective models calibrated to measurement data optimize micrometer-scale devices typical in displays.

Amorphous Materials Physics employs stochastic modeling of spatially varying band-edge landscapes, accounting for non-conducting band-tail states. This intrinsically captures material variability and applies to any disordered amorphous material.

Contact Modeling with Schottky-barrier contacts ensures realistic current-voltage characteristics, particularly for different contact metals like molybdenum and titanium used in display fabrication.

GTS Framework enables multiple levels of analysis to address different aspects of TFT development:

The DOE (Design of Experiments) workflow efficiently explores critical parameter spaces including density-of-states distribution, interface trap characteristics, material composition, and geometric dimensions.

Anisotropic mesh capabilities and efficient numerical methods enable practical simulation times even for three-dimensional structures. Validation of two-dimensional simulation accuracy through selective three-dimensional analysis allows optimal resource allocation.

Illumination stress represents a critical reliability concern for transparent oxide semiconductors. The reliability modeling framework includes carrier generation based on input light spectrum and material absorption. A chemical module handles ion reaction and diffusion mechanisms, with photogenerated carriers accelerating chemical reactions and degradation processes.