Plessey Semiconductors Ltd case study

Company background

Plessey Semiconductors Ltd is a UK-based leading developer of advanced optoelectronic technology solutions. The company provides volume processing of its unique and proprietary GaN-on-Silicon platform for a wide range of optoelectronic devices and systems. Plessey is an award-winning provider of innovative illuminators for display engines and full-field emissive microLED displays for head mounted displays (HMDs), Augmented Reality (AR) and Virtual Reality (VR) systems.

With headquarters located in Plymouth, Devon, Plessey operates leading-edge 150mm and 200mm wafer processing facilities to undertake design, test and assembly of products, and has a comprehensive suite of photonic characterisation and applications laboratories.

Plessey was the first SME to benefit from 30-hour support within PMCP. Below are three case studies that were undertaken on PEMC FIB-SEM.

Please follow the links on each case title for further information.

Case one: micro LED aligned bonding study

  • Micro LEDs have to be bonded to a CMOS back plane in order to control individual pixels on a display.
  • The bonding has to be accurately aligned, providing low resistance anode and cathode contacts between the CMOS back plane and LED display.
  • Early trials through in-house imaging by a single sourced FIB microscope at Plessey did not deliver the expected outcome and could not reveal the material issues. Read the full case study to find out how PEMC FIB-SEM helped. 

<p>Case 1: Micro LED aligned bonding study<br></p>

Case two: dead pixel study

  • Occasionally, pixels in LED chips are found unfunctional after the manufacturing process and have been precisely located by function testing.
  • An in-depth investigation is necessary in order to find evidence for the root cause.
  • Cross-sectioning by FIB and high-resolution SEM imaging are capable of delivering the material issues at hand, read the full case study to find out how this analysis has been carried out.


Case 2: Dead pixel study


Case three: faults investigation in LED chips

  • The existence of faults in between the built layers on silicon wafer would compromise the quality of the LED chips and cause a malfunction in a worse scenario. 
  • Conventional SEM imaging on the surface cannot reveal these potential imperfections under the surface.
  • FIB-SEM offers the capability of live monitoring by SEM during material etching by FIB, which permits the user to stop milling once faults or other features are exposed. 

<p>Plessey Semiconductors Ltd Case 3<br></p>

Company Feedback

“Having a local, state of the art tool, available to assist process development is a key resource for Plessey as we develop our LED processes to drive the mass adoption of micro LEDs in the display market.”

-- Mike Snaith (Chief Operating Officer at Plessey Semiconductors Ltd)


Plessey Semiconductors Ltd microLED<br></p>