| abstract |
A method for producing direct multilevel thin-film transistors (TFTs) with a small number of mask levels, for forming a contact between a transistor gate and the source or drain of the same or another transistor, and for use in producing flat LCD screens, particularly on screens having integral electronic control circuitry. Said method for producing direct multilevel thin-film transistors (20; 23; 24) having four mask levels comprises the steps of depositing and etching a first conductive level (11) on an insulating substrate (10) to form a source (1) and a drain (2), depositing and etching a semiconductor level (13) alone or followed by a first insulating level (16) joining the source (1) and the drain (2), depositing and etching a second insulating level (14), and depositing and etching a second conductive level (15) constituting the gate (22) of the transistor (20, 23). A further method of producing direct multilevel thin-film transistors (30) with three mask levels comprises the steps of depositing and etching a first conductive level (11) on an insulating substrate (10) to form a source and a drain (1, 2), depositing and a drain (1, 2), depositing a second semiconductor level (13) followed by an insulation level (16) and etching the assembly to join source (1) and drain (2), oxidation, nitriding or passivation of the sides (131, 132) of the semiconductor levels (13), and depositing and etching a conductive level (15). |