The Unique PostFlex Process

• Uses a sacrificial layer which can withstand high processing temperatures.
• Wide range of “Mother” substrate choices:
  Examples include Wacker Si sheets, fused silica, quartz sheets, metal substrates. Substrate choice dictates how high processing temperatures may go.
• Uses chemical/physical action to remove sacrificial layer.
• Can have final devices on glass or plastic final substrates, as desired.

Two Sacrificial Layer Removal Approaches

• Removal using front access vias/li>
• Removal using access from "mother" substrate; i.e. from the back

Front Access:

• Can finish full fabrication before separation
• Good when lost area due to access is not a problem. e.g. RFID tags, Smart Cards, sensors, etc.
• LC or EL display must be finished after separation

Back Access:

• Useful for all applications including displays, 3-D microelectronics
• No area is "lost"
• Devices (including LC or EL) can be completely finished before separation
• Final substrate can be glass or plastic

Key Features

• Cost-effective separation and transfer process
• Materials compatible with common semiconductor processes, including high-temperature processes for high performance devices such as CMOS circuitry
• Final substrate can be lightweight, low-cost flexible plastic, foil, glass, etc.
• Uses a high-temperature stable vacuum deposited sacrificial material (no electrochemical etching)
• Existing fabrication lines can be quickly adapted to run the PostFlex process
• Mother substrate is reusable
• Encapsulating medium can be final substrate or carrier for Positioning