| 摘要 |
PROBLEM TO BE SOLVED: To diffuse the residual thermal energy in a semiconductor substrate between heating pulse cycles by the insulation of the substrate from the heat of a heater element in the heating pulse of a heater element by accompanying with an SiO2 insulating layer immediately after a boron-phosphorus-doped silicate glass layer by providing the silicate glass layer directly under a heater on a chip. SOLUTION: A silicon dioxide layer 42 is provided on a substrate 34 under each heater 1, and a BPSG layer 39 is provided thereon. The combination of the layers 42 and 39 performs as a role of a heat barrier. A resistance material 44 is provided on the layer 39. When a current for driving the heater 1 is applied to a conductive layer, no electric route is provided except the heater 1, heat is generated by the current in the layer 44 in the region of the heater 1, and ink nucleus is formed. The combination thickness of the BPSG layer and SiO2 layer is decided so that the substrate is insulated in the heating pulse of the heater but the thermal energy is diffused in silicon during period of the time between the end of the pulse and the start-of the next cycle. |
