Methods of forming imaging device layers using carrier substrates
View Patent ↗An array of color filter elements may be formed over an array of photodiodes in an integrated circuit for an imaging device using a carrier substrate. The carrier substrate may have a planar surface with a release layer. A layer of color filter material may be applied to the release layer. The carrier substrate may then be flipped and the layer of color filter material may be bonded to the integrated circuit. Heat may be applied to activate the release layer and the carrier substrate may be removed at the interface between the release layer and the color filter material. The layer of color filter material may be patterned either before bonding the layer of color filter material or after the carrier substrate is removed. A layer of microlenses may be formed over the array of color filter elements using a carrier substrate.
1. A method of forming an array of color filter elements over an imaging device integrated circuit including an array of photodiodes in an imaging device, comprising:
depositing a layer of color filter material on a planar surface of a carrier substrate;
bonding the layer of color filter material to the imaging device integrated circuit;
while the layer of color filter material is bonded to the imaging device integrated circuit, removing the carrier substrate from the layer of color filter material; and
after removing the carrier substrate from the layer of color filter material, patterning the layer of color filter material to form the array of color filter elements on the integrated circuit.
2. The method of claim 1 , wherein the carrier substrate has a release layer.
3. The method of claim 2 , further comprising:
after depositing the layer of color filter material on the planar surface of the carrier substrate, heating the layer of color filter material such that the layer of color filter material adheres to the release layer.
4. The method of claim 3 , further comprising:
after heating the layer of color filter material such that the layer of color filter material adheres to the release layer, flipping the carrier substrate such that the layer of color filter material faces the imaging device integrated circuit, wherein bonding the layer of color filter material to the imaging device integrated circuit comprises bonding the layer of color filter material to the imaging device integrated circuit after the carrier substrate is flipped.
5. The method of claim 4 , wherein removing the carrier substrate comprises applying an amount of heat to the release layer, wherein the amount of heat applied is equal to or greater than a threshold of activation for the release layer.
6. The method of claim 4 , wherein removing the carrier substrate comprises removing the release layer and the carrier substrate at the interface between the release layer and the layer of color filter material.
7. A method of forming an imaging device, comprising:
depositing a color filter material layer over a release layer that is bonded to a planar surface of a carrier substrate;
applying heat to bond the color filter material layer to the release layer;
placing the color filter material layer in contact with an imaging device integrated circuit of the imaging device, wherein the imaging device integrated circuit comprises an array of photosensitive elements;
applying heat to the color filter material layer to bond the color filter material layer to the imaging device integrated circuit;
removing the carrier substrate at the interface between the release layer and the color filter material layer; and
patterning the color filter material layer to form an array of color filter elements, subsequent to removing the carrier substrate.
8. The method of claim 7 , wherein removing the carrier substrate at the interface between the release layer and the color filter material layer comprises removing the carrier substrate at the interface between the release layer and the color filter material layer.