Method for manufacturing interposer
A method for manufacturing an interposer equipped with a plurality of through-hole electrodes comprises a laser light converging step of converging a laser light at a sheet-like object to be processed made of silicon so as to form a modified region in the object; an etching step of anisotropically etching the object after the laser light converging step so as to advance etching selectively along the modified region and form a plurality of through holes in the object, each through hole being tilted with respect to a thickness direction of the object and having a rectangular cross section; an insulating film forming step of forming an insulating film on an inner wall of each through hole after the etching step; and a through-hole electrode forming step of inserting a conductor into the through holes so as to form the through-hole electrodes after the insulating film forming step; wherein the plurality of through holes are arranged such that the through holes aligning in the tilted direction are staggered in a direction perpendicular to the tilted direction as seen from a main face of the object.
1. A method for manufacturing an interposer equipped with a plurality of through-hole electrodes, the method comprising:
a laser light converging step of converging a laser light at a sheet-like object to be processed made of silicon so as to form a modified region in the object;
an etching step of anisotropically etching the object after the laser light converging step so as to advance etching selectively along the modified region and form a plurality of through holes in the object, each through hole having a rectangular cross section;
an insulating film forming step of forming an insulating film on an inner wall of each through hole after the etching step; and
a through-hole electrode forming step of inserting a conductor into the through holes so as to form the through-hole electrodes after the insulating film forming step;
wherein the plurality of through holes are aligned in rows, each through hole of one row having a different tilt angle with respect to a neighboring hole in the one row, and neighboring rows being arranged so that the through holes of the respective rows are staggered towards each other.
2. A method for manufacturing an interposer according to claim 1 , wherein the laser light converging step forms a first modified region as the modified region in a part corresponding to the through hole in the object and a second modified region as the modified region joining with the first modified region in a part to be removed upon thinning by the anisotropic etching; and
wherein the etching step advances the etching selectively along the second modified region and then along the first modified region while thinning the object to a target thickness and completes forming the through holes when the object is at the target thickness.
3. A method for manufacturing an interposer according to claim 2 , wherein the second modified region extends parallel to the thickness direction of the object.
4. A method for manufacturing an interposer according to claim 3 , wherein the object has a main face which is a (100) plane.
5. A method for manufacturing an interposer according to claim 4 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.
6. A method for manufacturing an interposer according to claim 3 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.
7. A method for manufacturing an interposer according to claim 2 , wherein the object has a main face which is a (100) plane.
8. A method for manufacturing an interposer according to claim 7 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.
9. A method for manufacturing an interposer according to claim 2 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.
10. A method for manufacturing an interposer according to claim 1 , wherein the second modified region extends parallel to the thickness direction of the object.
11. A method for manufacturing an interposer according to claim 10 , wherein the object has a main face which is a (100) plane.
12. A method for manufacturing an interposer according to claim 11 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.
13. A method for manufacturing an interposer according to claim 10 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.
14. A method for manufacturing an interposer according to claim 1 , wherein the object has a main face which is a (100) plane.
15. A method for manufacturing an interposer according to claim 14 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.
16. A method for manufacturing an interposer according to claim 1 , wherein the laser light converging step comprises:
a first step of repeatedly performing a step of irradiating the object with the laser light while relatively moving a converging point of the laser light along a first direction orthogonal to a laser light irradiation direction, while changing a depth position of the converging point in the irradiation direction; and
a second step of repeatedly performing the first step while changing a position of the converging point in a second direction orthogonal to the irradiation direction and first direction.