Improved thermal inkjet printhead structure and method for making the same.

摘要

An improved thermal inkjet printhead having MOSFET drive transistors (126) incorporated therein. The gate (110) of each MOSFET transistor (126) is formed by applying a layer (72) of silicon dioxide onto a silicon substrate (70), applying a layer (76) of silicon nitride onto the silicon dioxide, and applying a layer (90) of polycrystalline silicon onto the silicon nitride. Portions of the substrate (70) surrounding the gate (110) are oxidized, forming field oxide regions (84, 86). Source and drain regions (118, 120) are then conventionally formed, followed by the application of a protective dielectric layer (124) onto the field oxide (84, 86), source (118), drain (120), and gate (110). A resistive layer (180) is deposited on the dielectric layer (124) and directly connected to the source (118), drain (120), and gate (110). A conductive layer (181) is deposited on a portion of the resistive layer (180), ultimately forming both uncovered and covered regions (202, 204, 206) thereof. The uncovered region (202) functions as a heating resistor (209), and the covered regions (204, 206) function as electrical contacts to the transistor (126) and resistor (209).