Alloying method, and wiring forming method, display device forming method, and image display unit fabricating method

A wiring forming method comprising the steps of:

• transferring a semiconductor device having been formed on a semiconductor substrate to a material having a low thermal conductivity, and removing the semiconductor substrate from the semiconductor device;
• forming, as a wiring portion, a metal layer being in contact with the semiconductor device;
• and
• alloying an interface between the semiconductor device and the wiring portion by irradiating the interface between the semiconductor device and the wiring portion with a laser beam having a wavelength absorbable in at least one of the semiconductor device and the wiring portion.

A method of fabricating an image display unit in which display devices in the form of chips obtained by burying light emitting devices in a resin are arrayed in a matrix, said method comprising:

• a first transfer step of transferring light emitting devices having been arrayed on a first substrate to a temporarily holding member and holding the light emitting devices thereon in a state that the light emitting devices are enlargedly spaced from each other with a pitch larger than an array pitch of the light emitting devices on the first substrate;
• a second transfer step of transferring the light emitting devices having been held on the temporarily holding member to a second substrate in a state that the light emitting devices are more enlargedly spaced from each other with a pitch larger than the array pitch of the light emitting devices on the temporarily holding member;
• and
• a wiring forming step of forming a wiring portion connected to each of the light emitting devices;
• wherein said method further comprises:
• an electrode forming step of forming, after each of the light emitting devices made from a semiconductor is buried in a resin, an electrode composed of a metal layer on the surface of the resin;
• and
• an alloying step of alloying an interface between the light emitting device and the electrode by irradiating the interface between the light emitting device and the electrode with a laser beam having a wavelength absorbable in at least one of the semiconductor and the electrode.