Semiconductor device and fabricating method thereof
View Patent ↗A semiconductor device including a semiconductor substrate, a device isolation region formed by filling a trench in the semiconductor substrate with dielectric material and defining device regions in the semiconductor substrate. The trench has a rounded upper edge, and a dummy thin layer formed on the rounded upper edge.
1. A method for fabricating a semiconductor device, comprising steps of:
depositing a first sacrificial oxide layer and a first sacrificial nitride layer on a semiconductor substrate;
exposing the substrate by selectively removing the first sacrificial nitride layer and the first sacrificial oxide layer through an etch process;
forming a trench within the substrate by removing the exposed substrate;
forming a device isolation region by filling the trench with dielectric material, the device isolation region defining first and second device regions;
depositing a second sacrificial nitride layer and a second sacrificial oxide layer on the substrate;
removing the second sacrificial oxide layer and the second sacrificial nitride layer on the first device region through a selective etch process; and
forming a dummy thin layer along an edge of the trench close to the first device region by performing a high temperature thermal treatment on the substrate.
2. The method of claim 1 , wherein the step of forming a dummy thin layer includes forming a rounded edge of the trench, wherein the rounded edge is adjacent to the first device region.
3. The method of claim 2 , wherein the step of forming a dummy thin layer includes forming the dummy thin layer to be rounded along the rounded edge of the trench.
4. The method of claim 1 , wherein the step of forming a dummy thin layer includes performing a high temperature thermal treatment at a temperature of 1000° C. or higher.
5. A method for fabricating a semiconductor device, comprising:
a step for depositing a first sacrificial oxide layer and a first sacrificial nitride layer on a semiconductor substrate;
a step for exposing the substrate by selectively removing the first sacrificial nitride layer and the first sacrificial oxide layer through an etch process;
a step for forming a trench within the substrate by removing the exposed substrate;
a step for forming a device isolation region by filling the trench with dielectric material, the device isolation region defining first and second device regions;
a step for depositing a second sacrificial nitride layer and a second sacrificial oxide layer on the substrate;
a step for removing the second sacrificial oxide layer and the second sacrificial nitride layer on the first device region through a selective etch process; and
a step for forming a dummy thin layer along an edge of the trench close to the first device region by performing a high temperature thermal treatment on the substrate.
6. The method of claim 5 , wherein the step for forming a dummy thin layer includes a step for forming a rounded edge of the trench, wherein the rounded edge is adjacent to the first device region.
7. The method of claim 6 , wherein the step for forming a dummy thin layer includes a step for forming the dummy thin layer to be rounded along the rounded edge of the trench.
8. The method of claim 5 , wherein the step for forming a dummy thin layer includes a step for performing a high temperature thermal treatment at a temperature of 1000° C. or higher.