Ultraviolet radiation blocking interlayer dielectric
View Patent ↗A memory device may include a substrate, a first dielectric layer formed over the substrate and a charge storage element formed over the first dielectric layer. The memory device may also include a second dielectric layer formed over the charge storage element and a control gate formed over the second dielectric layer. The memory device may further include an interlayer dielectric formed over the control gate and the substrate, where the interlayer dielectric includes a material that is substantially opaque to ultraviolet radiation.
1. A memory device, comprising:
a substrate;
a first dielectric layer formed over the substrate;
a charge storage element formed over the first dielectric layer;
a second dielectric layer formed over the charge storage element;
a control gate formed over the second dielectric layer;
a single layer formed over the control gate and the substrate and physically contacting an upper surface of the substrate, the single layer comprising a first interlayer dielectric comprising a silicon-rich silicon nitride having a refractive index ranging from 2.2 to 2.5, where the silicon-rich silicon nitride has a thickness ranging from about 250 Å to about 650 Å;
at least one conductive layer formed over the single layer;
at least one second interlayer dielectric formed over the at least one conductive layer, the at least one second interlayer dielectric comprising a material that blocks at least 95 percent of ultraviolet radiation; and
another conductive layer formed over the at least one second interlayer dielectric, where the at least one second interlayer dielectric includes a contact hole that is filled by a metal layer that connects to the at least one conductive layer and the another conductive layer.
2. The memory device of claim 1 , further comprising:
a third interlayer dielectric formed over the first interlayer dielectric.
3. The memory device of claim 2 , where the third interlayer dielectric comprises boro-phosphosilicate glass.
4. A semiconductor device, comprising:
a plurality of memory cells formed on a substrate;
a continuous layer formed over the plurality of memory cells and physically contacting an upper surface of the substrate, the continuous layer comprising a first material having a refractive index of about 2.5, where the first material comprises a silicon-rich silicon nitride and has a thickness ranging from about 250 Å to about 650 Å;
a conductive layer formed over the continuous layer;
an interlayer dielectric formed over the conductive layer, the interlayer dielectric comprising a material that blocks at least 95 percent of ultraviolet radiation; and
another conductive layer formed over the interlayer dielectric, where the interlayer dielectric includes a contact hole that is filled by a metal layer that connects to the conductive layer and the another conductive layer.
5. The semiconductor device of claim 4 , where the continuous layer blocks at least 95 percent of ultraviolet radiation from reaching the plurality of memory cells.
6. The semiconductor memory device of claim 4 , where each of the plurality of memory cells comprises:
a tunnel layer formed over the substrate,
a charge storage element formed over the tunnel layer, the charge storage element comprising a dielectric material,
an inter-gate dielectric formed over the charge storage element, and
a control gate formed over the inter-gate dielectric.
7. The semiconductor device of claim 6 , where each of the plurality of memory cells is to store two bits of information.
8. A non-volatile memory device, comprising:
a substrate;
a first dielectric material formed over the substrate;
a charge storage element formed over the first dielectric material;
a second dielectric material formed over the charge storage element;
a control gate formed over the second dielectric material;
a continuous first interlayer dielectric formed over the control gate and physically contacting an upper surface of the substrate, the continuous first interlayer dielectric comprising a material that has a refractive index of about 2.5, and has a thickness ranging from about 250 Å to about 650 Å, where the first interlayer dielectric comprises a silicon-rich silicon nitride;
a conductive layer formed over the continuous first interlayer dielectric;
a second interlayer dielectric formed over the conductive layer, the second interlayer dielectric comprising a material that blocks at least 95 percent of ultraviolet radiation;
another conductive layer formed over the second interlayer dielectric, where the second interlayer dielectric includes a contact hole that is filled by a metal layer that connects to the conductive layer and the another conductive layer; and
a cap layer formed over the second interlayer dielectric, the cap layer comprising the material that has a refractive index of about 2.5.
9. The non-volatile memory device of claim 8 , where the continuous first interlayer dielectric blocks about 95 percent to about 100 percent of ultraviolet radiation from reaching the control gate.
10. The non-volatile memory device of claim 8 , where the charge storage element for each memory cell in the non-volatile memory device is to store two bits of information.
11. The non-volatile memory device of claim 8 , where the cap layer has a thickness ranging from about 6,000 Å to about 10,000 Å.
12. The non-volatile memory device of claim 8 , where the cap layer blocks at least 95 percent of ultraviolet radiation.