Method for manufacturing a semiconductor device

1. A method for manufacturing a semiconductor device comprising:

forming a removal layer over a base;

forming an interconnect layer over said removal layer;

mounting semiconductor chip(s) over said interconnect layer; and

separating said base from said interconnect layer while inducing the separation so as to originate from said removal layer, by irradiating a laser having a wavelength transparent with respect to said base from the back side thereof, selectively to an unmounted region having no semiconductor chip(s) mounted thereon.

2. The method for manufacturing a semiconductor device as claimed in claim 1 ,

wherein in said mounting said semiconductor chip(s),

a plurality of said semiconductor chips are mounted over said interconnect layer, and

wherein said separating said base from said interconnect layer further includes:

irradiating said laser along dicing lines used for singulating semiconductor devices.

3. The method for manufacturing a semiconductor device as claimed in claim 1 , wherein separating said interconnect layer allows said removal layer to generate a gas, upon irradiation of said laser to said removal layer.

4. The method for manufacturing a semiconductor device as claimed in claim 3 , wherein said removal layer contains at least one compound selected from the group consisting of metal oxide, metal nitride and metal oxinitride.

5. The method for manufacturing a semiconductor device as claimed in claim 1 , wherein said base is composed of glass, quartz glass, sapphire, aluminum nitride or silicon.

6. The method for manufacturing a semiconductor device as claimed in claim 1 , wherein said interconnect layer is composed of a resin layer formed over said base, and a metal layer buried in said resin layer, and

wherein the method further comprises, after said forming said interconnect layer, and before said separating said base from said interconnect layer:

forming an alignment mark by irradiating a laser having a wavelength transparent with respect to said base from the back side thereof to modify said removal layer or a portion of said resin layer composing said interconnect layer, and

wherein said separating said base from said interconnect layer further includes:

positioning said laser irradiation making use of said alignment mark.

7. The method for manufacturing a semiconductor device as claimed in claim 6 , wherein said forming said alignment mark includes:

forming said alignment mark recognizable from the back side of said base from a part of said metal layer by irradiating said laser from the back side of said base to modify a portion of said removal layer into a transparent portion.

8. The method for manufacturing a semiconductor device as claimed in claim 6 , wherein said forming said alignment mark includes:

forming an alignment mark by irradiating said laser having a wavelength transparent with respect to said base from the back side thereof to modify a portion of said interconnect layer.

9. The method for manufacturing a semiconductor device as claimed in claim 1 , wherein said separating said base from said interconnect layer includes:

immersing said base having said semiconductor chip(s) mounted thereon into a separation liquid, so as to allow said separation liquid to infiltrate into the interface between said base and said removal layer, to thereby induce the separation.

10. A method for manufacturing a semiconductor device comprising:

forming a removal layer over a base;

forming an interconnect layer over said removal layer, said interconnect later composes of a resin layer formed over said base, and a metal layer buried in said resin layer;

forming an alignment mark by irradiating a laser having a wavelength transparent with respect to said base from the back side thereof to modify said removal layer or a portion of said resin layer composing said interconnect layer;

mounting semiconductor chip(s) over said interconnect layer; and

separating said base from said interconnect layer while inducing the separation so as to originate from said removal layer, by irradiating a laser having a wavelength transparent with respect to said base from the back side thereof,

wherein said alignment mark is used for positioning of said laser irradiation.

11. The method for manufacturing a semiconductor device as clsimed in claim 10 , wherein said removal layer includes one of a metal oxide, a metal nitride, and a metal oxynitride.

12. The method for manufacturing a semiconductor device as claimed in claim 10 ,

wherein in said mounting said semiconductor chip(s), a plurality of said semiconductor chips are mounted over said interconnect layer, and

wherein said separating said base from said interconnect layer further includes:

irradiating said laser along dicing lines used for singulating semiconductor devices.

13. The method for manufacturing a semiconductor device as claimed in claim 10 , wherein separating said interconnect layer allows said removal layer to generate a gas, upon irradiation of said laser to said removal layer.

14. The method for manufacturing a semiconductor device as claimed in claim 10 , wherein said base is composed of glass, quartz glass, sapphire, aluminum nitride or silicon.

15. The method for manufacturing a semiconductor device as claimed in claim 10 , wherein said forming said alignment mark includes:

forming said alignment mark recognizable from the back side of said base from a part of said metal layer by irradiating said laser from the back side of said base to modify a portion of said removal layer into a transparent portion.

16. The method for manufacturing a semiconductor device as claimed in claim 10 , wherein said forming said alignment mark includes:

forming an alignment mark by irradiating said laser having a wavelength transparent with respect to said base from the back side thereof to modify a portion of said interconnect layer.

17. The method for manufacturing a semiconductor device as claimed in claim 10 , wherein said separating said base from said interconnect layer includes:

immersing said base having said semiconductor chip(s) mounted thereon into a separation liquid, so as to allow said separation liquid to infiltrate into the interface between said base and said removal layer, to thereby induce the separation.