Selective micro device transfer to receiver substrate
A method of selectively transferring micro devices from a donor substrate to contact pads on a receiver substrate. Micro devices being attached to a donor substrate with a donor force. The donor substrate and receiver substrate are aligned and brought together so that selected micro devices meet corresponding contact pads. A receiver force is generated to hold selected micro devices to the contact pads on the receiver substrate. The donor force is weakened and the substrates are moved apart leaving selected micro devices on the receiver substrate. Several methods of generating the receiver force are disclosed, including adhesive, mechanical and electrostatic techniques.
1. A method to remove defective optoelectronic devices, the method comprising:
putting a receiver substrate in a test mode to identify the defective optoelectronic devices in the receiver substrate;
biasing a pixel in the receiving substrate for activating or deactivating the optoelectronic devices for identifying the defective optoelectronic devices;
removing or fixing the defective optoelectronic devices;
after the removing or fixing, post processing to permanently bond the optoelectronic devices into the receiver substrate; and
extracting optical characteristics of the optoelectronic devices using a sensor or a sensor array.
2. The method of claim 1 , wherein multiple bias points are applied to the optoelectronic devices to extract the optical characteristics of the micro devices.
3. The method of claim 1 , wherein a selected set of optoelectronic devices are biased in the receiver substrate to be active.
4. The method of the claim 3 , wherein inactive biased optoelectronic devices are flagged as defective.
5. The method of claim 3 , wherein the selected set of optoelectronic devices are biased to be inactive and the active devices in the selected set are flagged as defective.