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Technology Ventures

Localized fabrication of polysilicon microstructures using a lithographic and silicon crystallization process

Technology #m08-064

High performance thin film transistors (TFT) can be fabricated on polysilicon films obtained by super lateral growth (SLG). Due to the uncontrolled nature of domains obtained through the SLG process, several techniques collectively named sequential lateral solidification (SLS) are used to control the grain size and orientation. However, the present form of SLS cannot control the location of the microstructures on which devices are patterned resulting in non-uniform devices at different locations. This drawback may cause a major roadblock for TFT applications where more stringent parameters are needed. This technology addresses this problem by describing a method for achieving localized and defined microstructural domains. The ability to create uniform distribution of silicon crystallization as embodied in this technology allows for improved performance in devices utilizing silicon film microstructures.

Lithography-based approach for SLS controls location control of microstructures and consumes lower operating costs

Current SLS methods for manufacturing film microstructures lack spatial control over their location and pattern. This can negatively affect applications such as Active Matrix Organic Light Emitting Diodes (AMOLEDs) where device uniformity is important for performance. This technology describes a form of SLS in which lithographically defined openings are treated with SLS processes. This results in a localized melting of silicon, thereby giving location defined microstructure domains. By utilizing a lithography-based approach in combination with existing crystallization methods, this technology can achieve better control of microstructure location and orientation. In addition, the technology is also cost effective since it uses cheaper radiation sources such as flash lamps during the SLS process.

Lead Inventor:

James Im, Ph.D.

Applications:

  • Fabrication of AMOLEDs (Active Matrix Organic Light Emitting Diodes), AMLCDs (Active Matrix LCD), and other types display screens where fabrication parameters are stringent.
  • Non-planar or 3-D integrated circuits
  • Thin film polysilicon photovoltaic solar cells

Advantages:

  • Resulting microstructures can be aligned well with thin film transistor channel regions.
  • Allows for significant improvent in device uniformity and performance
  • Will make the existing processes useful for next generation AMOLED displays
  • Cost-effective method for making solar cells using thin film polysilicon photovoltaics
  • Can be used with cheaper radiation sources (e.g. flash lamps) in SLS processes

Patent information:

Patent Pending (US 20110175099)

Licensing Status:

Available for licensing and sponsored research support

Tech Ventures Reference: IR M08-064

Related Publications:

Further Information:
Columbia | Technology Ventures Email: TechTransfer@columbia.edu