Semiconductor devices and methods for forming patterned radiation blocking on a semiconductor device
View Patent ↗Several embodiments for semiconductor devices and methods for forming semiconductor devices are disclosed herein. One embodiment is directed to a method for manufacturing a microelectronic imager having a die including an image sensor, an integrated circuit electrically coupled to the image sensor, and electrical connectors electrically coupled to the integrated circuit. The method can comprise covering the electrical connectors with a radiation blocking layer and forming apertures aligned with the electrical connectors through a layer of photo-resist on the radiation blocking layer. The radiation blocking layer is not photoreactive such that it cannot be patterned using radiation. The method further includes etching openings in the radiation blocking layer through the apertures of the photo-resist layer.
1. A method of manufacturing a microelectronic imager having a substrate, an imager sensor located at a first side of the substrate, integrated circuitry coupled to the image sensor, and a bond-pad at the first side of the substrate, the method comprising:
forming a redistribution structure having a through-substrate interconnect and a trace electrically coupled to the through-substrate interconnect, the through-substrate interconnect extending from the bond-pad to a second side of the substrate and the trace extending over the second side of the substrate, and the second side of the substrate being opposite the first side of the substrate;
disposing a preformed first material over the trace, the preformed first material including a non-photoreactive radiation blocking material;
shaping the first material to conform to the redistribution structure;
disposing a second material on the preformed first material, the second material including a photoreactive material;
forming an aperture in the second material, the aperture being generally in alignment with the trace; and
forming an opening in the preformed first material through the aperture to expose a portion of the trace.
2. The method of claim 1 wherein:
the preformed first material is a first preformed sheet having a first thickness and the second material is a second preformed sheet laminated to the first preformed sheet, the first and second preformed sheets forming a laminated bi-layer structure before disposing the preformed first material over the trace;
disposing the preformed first material over the trace comprises placing the laminated bi-layer structure on the redistribution structure under a vacuum with the first preformed sheet below the second preformed sheet and releasing the vacuum to conform the laminated bi-layer structure to the topography of the redistribution structure; and
forming the aperture in the second material comprises exposing the second preformed sheet to a pattern of radiation energy and developing the second preformed sheet thereby forming the aperture in the second preformed sheet through which the opening is etched in the preformed first material.
3. The method of claim 1 wherein the preformed first material comprises a first preformed sheet of an IR blocking material having a first thickness and the second material comprises a second preformed sheet, and wherein the method further comprises laminating the first and second preformed sheets together before disposing the preformed first material over the trace.
4. The method of claim 3 wherein the first preformed sheet comprises a carbon black material and the second preformed sheet comprises a dry resist.
5. The method of claim 1 wherein the preformed first material comprises a first preformed sheet of an IR blocking material and the method further comprises forming a laminated bi-layer structure by disposing the second material onto the first performed sheet.
6. The method of claim 5 wherein the second material comprises a dry resist and disposing the second material onto the first preformed sheet comprises depositing the dry resist on the first preformed sheet.
7. The method of claim 6 wherein the dry resist is deposited onto the first performed sheet before disposing the preformed first material over the trace.
8. The method of claim 1 wherein disposing the preformed first material over the trace comprises depositing a conformal layer of IR blocking material over the second side of the substrate.
9. The method of claim 1 wherein the preformed first material comprises a first preformed sheet of a carbon black material and the second material comprises a second preformed sheet of a dry resist, and wherein the method further comprises laminating the first and second preformed sheets together before disposing the preformed first material over the trace.
10. The method of claim 1 , further comprising disposing the second material on the preformed first material via a spin-on process.
11. The method of claim 1 , further comprising:
forming the aperture in the second material by drying etching the second material.
12. The method of claim 1 , further comprising:
forming the opening in the preformed first material through the aperture by drying etching the preformed first material through the aperture.
13. The method of claim 1 , further comprising:
selecting a thickness of at least one of the first and second materials such that a target thickness of both the first and second materials remain on the second side of the substrate after exposing the portion of the trace.