Method of dicing a semiconductor device into plural chips

1. A method of manufacturing a semiconductor device comprising:

providing a substrate having effective chip areas, the chip areas being separated from each other by dicing areas, wherein the substrate has a first layer with a semiconductor element on the first layer, and a second layer on the first layer and covering the semiconductor element, the second layer including a post electrically connected to the semiconductor element in the effective chip area, a top surface of the post exposed from the second layer, wherein permeability of the second layer to laser light is lower than permeability of the first layer to laser light;

grinding an entire surface of the first layer of the substrate;

removing the second layer in the dicing areas; and

applying laser light to the first layer of the ground substrate at the dicing areas, to cut the ground substrate into plural chips.

2. The method of manufacturing a semiconductor device of claim 1 , wherein said applying laser light is a non-fusion process performed by converging the laser light inside the ground substrate.

3. The method of manufacturing a semiconductor device of claim 1 , wherein the substrate is a silicon substrate.

4. The method of manufacturing a semiconductor device of claim 1 , wherein the substrate includes a silicon thin film on a sapphire substrate.

5. The method of manufacturing a semiconductor device of claim 1 , wherein the second layer includes a seal layer that seals the semiconductor element and the first layer.

6. The method of manufacturing a semiconductor device of claim 1 , wherein the first layer of the substrate is ground during said grinding to have a thickness through which the laser light may pass, and the laser light is applied to the ground side of the first layer of the substrate.

7. A method of manufacturing a semiconductor device comprising:

providing a substrate having effective chip areas, the chip areas being separated from each other by dicing areas, wherein the substrate has a first layer and a second layer on the first layer, the second layer including a semiconductor element formed on the first layer and a seal layer covering the semiconductor element, a permeability of the second layer to laser light is lower than a permeability of the first layer to laser light;

fixing the second layer on a first elastic sheet;

grinding the first layer of the substrate;

applying laser light to the ground first layer of the substrate at the dicing areas, to cut the ground first layer of the substrate;

removing the first elastic sheet;

fixing the first layer on a second elastic sheet; and

expanding the second elastic sheet to separate the cut substrate into plural chips.

8. The method of manufacturing a semiconductor device of claim 7 , wherein said applying laser light is a non-fusion process performed by converging the laser light inside the ground substrate.

9. The method of manufacturing a semiconductor device of claim 7 , wherein the substrate is a silicon substrate.

10. The method of manufacturing a semiconductor device of claim 7 , wherein the substrate includes a silicon thin film on a sapphire substrate.

11. The method of manufacturing a semiconductor device of claim 7 , wherein said grinding the first layer comprises:

grinding an entire surface of the first layer to a first smoothness; and

grinding the ground first layer to a second smoothness, the second smoothness being smoother than the first smoothness.

12. The method of manufacturing a semiconductor device of claim 7 , wherein the first layer of the substrate is ground during said grinding to have a thickness through which the laser light may pass.