Patent ID: 8802462

Claim:
A method for manufacturing a display device including a display portion including a plurality of pixels; a pixel circuit provided in each of the plurality of pixels and including a display element and a first transistor; a sensor circuit provided in all or part of the plurality of pixels and including an optical sensor and a second transistor; a pixel driver circuit electrically connected to the pixel circuit and including a third transistor; and a sensor driver circuit electrically connected to the sensor circuit and including a fourth transistor, comprising the steps of: preparing a single crystal semiconductor substrate and a supporting substrate; forming a damaged region in a region at a predetermined depth from a surface of the single crystal semiconductor substrate by adding ions to the single crystal semiconductor substrate; forming a buffer layer over at least one of the supporting substrate and the single crystal semiconductor substrate; bonding the single crystal semiconductor substrate to the supporting substrate with the buffer layer interposed therebetween; forming the supporting substrate to which a single crystal semiconductor layer separated from the single crystal semiconductor substrate is provided, by generating a crack in the damaged region by heating of the single crystal semiconductor substrate so that the single crystal semiconductor substrate is separated from the supporting substrate; forming a plurality of single crystal semiconductor layers by dividing the single crystal semiconductor layer among elements; and forming the first transistor, the second transistor, the third transistor, the fourth transistor and a photoelectric conversion layer of the optical sensor using the divided single crystal semiconductor layer, wherein the ions include H + , H 2 + and H 3 + , and wherein H 3 + is included in the ions at greater than or equal to 50%.