Self-aligned photolithographic process for forming silicon-on-insulator devices
OwnerBenjamin Szu-Min Lininventor
Life of this patent
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Abstract
A self-aligned photolithographic process for forming silicon-on-insulator devices. A substrate made from a transparent insulating material is provided. Conductive devices made from a non-transparent material, material layers made from transparent material and a photoresist layer are formed over the substrate. Transparent substrate areas having conductive devices thereon are non-transparent regions and transparent substrate areas having no conductive devices thereon are transparent regions. Using the substrate as a mask, a contact exposure of the photoresist material is conducted to form a patterned photoresist layer by shining light through the transparent substrate regions.
Claims18
A self-aligned photolithographic process for forming a silicon-on-insulator device, comprising:
- providing a substrate having a plurality of conductive devices formed thereon, wherein the substrate is made from a transparent material and the conductive devices are made from a non-transparent material;
- forming a material layer over the substrate, wherein the material layer is made from a transparent material;
- forming a photoresist layer over the material layer;
- conducting a contact exposure of the photoresist layer by shining a beam of light from a light source through the transparent regions of the substrate while using the substrate itself as a mask, wherein substrate areas having conductive devices thereon are non-transparent regions and substrate areas having no conductive devices thereon are transparent regions;
- and
- performing a post-exposure chemical development to form a pattern on the photoresist layer.
A self-aligned photolithographic process for forming a silicon-on-insulator device, comprising:
- providing a substrate, wherein the substrate is made from a transparent material;
- forming an active device layer over the substrate, wherein the active device layer is made from a non-transparent material;
- forming an isolation layer over the substrate on each side of the active device layer, wherein the isolation layer is made from a transparent material;
- forming a plurality of word lines over the substrate, wherein the word lines are formed over a portion of the active device layer and a portion of the isolation layers, and each word line further includes a first conductive layer, a cap layer and a spacer on sidewalls of the first conductive layer and the cap layer;
- forming an insulation layer over the substrate, wherein the insulation layer is made from a transparent material;
- forming a photoresist layer over the insulation layer, conducting a contact exposure of the photoresist layer by shining a beam of light from a light source through the transparent regions of the substrate, wherein the active device layer and the word lines over the substrate are non-transparent regions and the isolation layers having no word lines thereon are transparent regions;
- performing a post-exposure photoresist development to form a patterned photoresist layer, wherein the patterned photoresist layer covers the transparent region;
- removing the insulation layer outside the photoresist covered region using the patterned photoresist layer as a mask to form a plurality of openings in the active device region;
- removing the patterned photoresist layer;
- forming a second conductive layer over the substrate such that the second conductive layer also completely fills the openings;
- and
- removing a portion of the second conductive layer and the insulation layer to expose the cap layer so that a plurality of conductors is formed inside the openings.
Dependencies are inferred from the claim text.