Semiconductor light-emitting device and method for separating semiconductor light-emitting devices
First Claim
1. A method for separating semiconductor light-emitting devices formed on a substrate, said method comprising focusing a pulse laser beam having a pulse width less than 10 ps in said substrate, to thereby cause multi-photon absorption in said substrate;
- forming a surface structurally changed portion by means of said pulse laser beam along a split line predetermined on a surface of said substrate;
forming internal structurally changed portions through said pulse laser beam at a predetermined depth of said substrate on a predetermined split face, said internal structurally changed portions being discontinuous in a direction of said predetermined split line; and
applying an external force to thereby form a split face along said surface structurally changed portion and said discontinuous internal structurally changed portions, whereby said semiconductor light-emitting devices are separated from one another.
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Abstract
The invention provides a method for separating semiconductor light-emitting devices formed on a substrate. In the method, a pulse laser beam having a pulse width less than 10 ps in a substrate is focused on the substrate, to thereby cause multi-photon absorption in the substrate. Through multi-photon absorption, a groove is formed through the pulse laser beam along a split line predetermined on a surface of the substrate, the groove being substantially continuous in the direction of the predetermined split line. In addition, internal structurally changed portions are formed through the pulse laser beam at a predetermined depth of the substrate on a predetermined split face, the structurally changed portions being discontinuous in the direction of the predetermined split line. Subsequently, an external force is applied to thereby form a split face along the continuous groove and the discontinuous internal structurally changed portions, whereby the semiconductor light-emitting devices are separated from one another
132 Citations
25 Claims
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1. A method for separating semiconductor light-emitting devices formed on a substrate, said method comprising
focusing a pulse laser beam having a pulse width less than 10 ps in said substrate, to thereby cause multi-photon absorption in said substrate; -
forming a surface structurally changed portion by means of said pulse laser beam along a split line predetermined on a surface of said substrate;
forming internal structurally changed portions through said pulse laser beam at a predetermined depth of said substrate on a predetermined split face, said internal structurally changed portions being discontinuous in a direction of said predetermined split line; and
applying an external force to thereby form a split face along said surface structurally changed portion and said discontinuous internal structurally changed portions, whereby said semiconductor light-emitting devices are separated from one another. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for separating semiconductor light-emitting devices, including splitting a wafer into individual semiconductor light-emitting device chips, said wafer comprising a transparent substrate having a first surface, and a second surface parallel to the first surface, and a semiconductor layer containing a light-emitting layer and deposited on the first surface of said transparent substrate, wherein the method comprises
a first internal processing step including causing a pulse laser beam having a wavelength ensuring optical transparency with respect to said wafer to enter said wafer through said first or second surface serving as an incident face by the mediation of a condensing lens, while a focus of the condensing lens is adjusted such that a waist, which is a pulse laser beam focused portion, is present in said wafer; -
shifting an optical axis of said pulse laser beam relative to an incident face and along an imaginary split line predetermined on said wafer such that waists formed from said pulse beams provided by said pulse laser beam are spatially separated from one another; and
at every incidence of said pulse beam of said pulse laser beam on said incident face, embrittling a portion of said wafer corresponding to said waist through multi-photon absorption, to thereby form discontinuous light-induced embrittled portions; and
a grooving processing step including adjusting said focus of said condensing lens such that a waist formed by said pulse laser beam is present in a surface portion of said incident face of said wafer;
shifting said optical axis of said pulse laser beam relative to said incident face and along said split line such that waists formed from said pulse beams provided by said pulse laser beam are spatially connected to or overlapped with one another; and
at every incidence of the pulse beam of the pulse laser beam on the incident face, embrittling a portion of the wafer corresponding to the waist through multi-photon absorption, to thereby form a continuous groove, wherein each of the semiconductor light-emitting device chips has a split face provided with indents/protrusions. - View Dependent Claims (22, 23, 24)
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25. A semiconductor light-emitting device, including a transparent substrate having a first surface, and a second surface parallel to the first surface, and a semiconductor layer containing a light-emitting layer and deposited on said first surface, wherein said semiconductor light-emitting device separated from a wafer has a split face provided with indents/protrusions.
Specification