Method of forming a multilayer structure for reducing defects in semiconductor devices and structure
View Patent ↗A method of forming a semiconductor device includes providing a semiconductor substrate and forming amorphous semiconductor layers adjacent a major surface of the substrate. The method includes interposing dielectric layers between the amorphous semiconductor layers. The method includes forming polycrystalline semiconductor layers adjacent the amorphous semiconductor layers. The method includes interposing dielectric layers between the polycrystalline semiconductor layers and between the last amorphous semiconductor layer and the first polycrystalline semiconductor layer. The method includes forming a fine-grain polycrystalline semiconductor layer adjacent the polycrystalline semiconductor layers but is separated from the last polycrystalline semiconductor layer by an additional dielectric layer. The fine-grain polycrystalline semiconductor layer is formed at a higher temperature than the polycrystalline semiconductor layers and the amorphous semiconductor layers. A semiconductor device can be formed in another major surface of the semiconductor substrate.
1. A method of forming a semiconductor device comprising:
providing a semiconductor substrate having a first major surface and an opposing second major surface;
forming first semiconductor layers adjacent the second major surface, wherein the first semiconductor layers each comprise an amorphous semiconductor material, and wherein forming the first semiconductor layers comprises forming first non-conductive layers interposed between each of the first semiconductor layers, and wherein the first semiconductor layers are each formed at a first temperature in a first temperature range;
forming a second non-conductive layer adjacent an outermost one of the first semiconductor layers;
forming second semiconductor layers adjacent the second non-conductive layer, wherein the second semiconductor layers each comprise a polycrystalline semiconductor material, and wherein forming the second semiconductor layers comprises forming third non-conductive layers interposed between each of the second semiconductor layers, and wherein the second semiconductor layers are each formed at a second temperature in a second temperature range;
forming a fourth non-conductive layer adjacent an outermost one of the second semiconductor layers;
forming a third semiconductor layer adjacent the fourth non-conductive layer at a third temperature in a third temperature range, wherein the third semiconductor layer comprises a polycrystalline semiconductor material, and wherein the third temperature range is higher than the first temperature range; and
forming a semiconductor device adjacent the first major surface.
2. The method of claim 1 , wherein forming the first semiconductor layers comprises forming amorphous silicon layers.
3. The method of claim 2 , wherein forming the amorphous silicon layers comprises forming first dielectric layers interposed between each of the amorphous silicon layers.
4. The method of claim 3 , wherein forming the first dielectric layers comprises forming oxide layers each having a thickness in a range from about 10 Angstroms to about 1000 Angstroms.
5. The method of claim 2 , wherein the first temperature range is from about 550 degrees Celsius through about 590 degrees Celsius.
6. The method of claim 5 , wherein forming the amorphous silicon layers comprises forming the amorphous silicon layers each having a thickness in a range from about 10 Angstroms through about 10,000 Angstroms.
7. The method of claim 1 , wherein forming the second non-conductive layer comprises forming an oxide layer.
8. The method of claim 1 , wherein forming the second semiconductor layers comprises forming polysilicon layers.
9. The method of claim 8 , wherein forming the second semiconductor layers comprises forming second dielectric layers interposed between each of the polysilicon layers.
10. The method of claim 9 , wherein forming the second dielectric layers comprises forming oxide layers each having a thickness in a range from about 10 Angstroms to about 1000 Angstroms.
11. The method of claim 8 , wherein the second temperature range is from about 600 degrees Celsius through about 640 degrees Celsius.
12. The method of claim 8 , wherein forming the polysilicon layers comprises forming the polysilicon layers each having a thickness in range from about 10 Angstroms through about 1000 Angstroms.
13. The method of claim 1 , wherein forming the third semiconductor layer comprises forming a polycrystalline semiconductor layer.
14. The method of claim 13 , wherein forming the polycrystalline semiconductor layer comprises forming a polysilicon layer, wherein the third temperature range is from about 640 degrees Celsius through about 650 degrees Celsius.
15. The method of claim 14 , wherein forming the fourth non-conductive layer comprises forming an oxide layer at a fourth temperature in the third temperature range.
16. The method of claim 14 , wherein forming the polysilicon layer comprises forming the polysilicon layer having a thickness in a range from about 1000 Angstroms through about 2000 Angstroms.
17. The method of claim 1 , wherein the steps of forming the first semiconductor layers, forming the second non-conductive layer, forming the second semiconductor layers, forming the fourth non-conductive layer, and forming the third semiconductor layer are carried out in a single processing apparatus without exposing the semiconductor substrate outside of the processing apparatus until after the third semiconductor layer is formed.
18. A method for forming a semiconductor device structure comprising the steps of:
a. providing a semiconductor substrate having a first major surface and an opposing second major surface;
b. forming first semiconductor layers adjacent the second major surface, wherein the first semiconductor layers each comprise an amorphous semiconductor material, and wherein forming the first semiconductor layers comprises forming first non-conductive layers interposed between each of the first semiconductor layers, and wherein the first semiconductor layers and the first non-conductive layers are each formed at a temperature in a first temperature range, wherein the first semiconductor layers each have an as-formed compressive stress;
c. forming a second non-conductive layer adjacent an outermost one of the first semiconductor layers;
d. forming second semiconductor layers adjacent the second non-conductive layer, wherein the second semiconductor layers each comprise a polycrystalline semiconductor material, and wherein forming the second semiconductor layers comprises forming third non-conductive layers interposed between each of the second semiconductor layers, and wherein the second semiconductor layers and the third non-conductive layers are each formed at a temperature in a second temperature range;
e. forming a fourth non-conductive layer adjacent an outermost one of the second semiconductor layers;
f. forming a third semiconductor layer adjacent the fourth non-conductive layer at a temperature in a third temperature range, wherein the third semiconductor layer comprises a polycrystalline semiconductor material, and wherein the third temperature range is higher than the first temperature range, and wherein the first semiconductor layers recrystallize during step f to provide the first semiconductor layers having tensile stress; and
g. forming a semiconductor device structure adjacent the first major surface, wherein:
the first semiconductor layers are configured to compensate for stress induced by the second semiconductor layers on the semiconductor substrate to reduce warpage of the semiconductor substrate;
the second semiconductor layers are configured to provide extrinsic gettering of the semiconductor substrate; and
the third semiconductor layer is configured to reduce defect formation in the semiconductor substrate.
19. The method of claim 18 , wherein:
steps b through f are carried out in a single deposition run;
forming the first semiconductor layers comprises forming amorphous silicon layers where the first temperature range is from about 550 degrees Celsius through about 590 degrees Celsius;
forming the first non-conductive layers comprises forming oxide layers;
forming the second semiconductor layer comprises forming polysilicon layers where the second temperature range is from about 600 degrees Celsius through about 640 degrees Celsius;
forming the second non-conductive layers comprises forming oxide layers;
forming the fourth non-conductive layer comprises forming an oxide layer in the third temperature range; and
forming the third semiconductor layer comprises forming another polysilicon layer where the third temperature range is from about 640 degrees Celsius through about 650 degrees Celsius.
20. A method for forming a semiconductor device structure comprising the steps of:
a. providing a semiconductor substrate having a first major surface and an opposing second major surface;
b. forming first semiconductor layers adjacent the second major surface, wherein the first semiconductor layers each comprise an amorphous semiconductor material, and wherein forming the first semiconductor layers comprises forming first non-conductive layers interposed between each of the first semiconductor layers, and wherein the first semiconductor layers and the first non-conductive layers are each formed at a temperature in a first temperature range, wherein the first semiconductor layers each have an as-formed compressive stress;
c. forming a second non-conductive layer adjacent an outermost one of the first semiconductor layers;
d. forming second semiconductor layers adjacent the second non-conductive layer, wherein the second semiconductor layers each comprise a polycrystalline semiconductor material, and wherein forming the second semiconductor layers comprises forming third non-conductive layers interposed between each of the second semiconductor layers, and wherein the second semiconductor layers and the third non-conductive layers are each formed at a temperature in a second temperature range;
e. forming a fourth non-conductive layer adjacent an outermost one of the second semiconductor layers;
f. forming a third semiconductor layer adjacent the fourth non-conductive layer at a temperature in a third temperature range, wherein the third semiconductor layer comprises a polycrystalline semiconductor material, and wherein the third temperature range is higher than the first temperature range, and wherein the first semiconductor layers recrystallize during step f to provide the first semiconductor layers having tensile stress; and
g. forming a semiconductor device structure adjacent the first major surface, wherein:
steps b through f are carried out in a single deposition run;
the first semiconductor layers are configured to compensate for stress induced by the second semiconductor layers on the semiconductor substrate to reduce warpage of the semiconductor substrate;
the second semiconductor layers are configured to provide extrinsic gettering of the semiconductor substrate; and
the third semiconductor layer is configured to reduce defect formation in the semiconductor substrate.