Method for manufacturing a semiconductor device using an oxide semiconductor
First Claim
1. A method for manufacturing a semiconductor device, comprising the steps of:
- forming a gate electrode layer having a light-blocking property over a first surface of a substrate;
forming a gate insulating film over the gate electrode layer;
forming an island-shaped oxide semiconductor layer having a light-transmitting property over the gate insulating film;
forming an insulating layer over the island-shaped oxide semiconductor layer;
forming a positive photosensitive thin film over the insulating layer;
performing light exposure on the positive photosensitive thin film by irradiation with light from a side of the substrate opposite to the first surface;
removing an exposed region of the positive photosensitive thin film by development;
forming a channel protective layer by etching the insulating layer with the use of an unexposed region of the positive photosensitive thin film as a mask; and
forming a wiring layer over the island-shaped oxide semiconductor layer.
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Abstract
In a manufacturing process of a semiconductor device formed using a thin film transistor, an object is to provide a technique by which the number of photomasks can be reduced, manufacturing cost can be reduced, and improvement in productivity and reliability can be achieved. A main point is that a film forming a channel protective layer is formed over an oxide semiconductor layer having a light-transmitting property, a positive photoresist is formed over the film forming a channel protective layer, and a channel protective layer is selectively formed over a channel formation region in the oxide semiconductor layer by using a back surface light exposure method.
127 Citations
13 Claims
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1. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode layer having a light-blocking property over a first surface of a substrate; forming a gate insulating film over the gate electrode layer; forming an island-shaped oxide semiconductor layer having a light-transmitting property over the gate insulating film; forming an insulating layer over the island-shaped oxide semiconductor layer; forming a positive photosensitive thin film over the insulating layer; performing light exposure on the positive photosensitive thin film by irradiation with light from a side of the substrate opposite to the first surface; removing an exposed region of the positive photosensitive thin film by development; forming a channel protective layer by etching the insulating layer with the use of an unexposed region of the positive photosensitive thin film as a mask; and forming a wiring layer over the island-shaped oxide semiconductor layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification
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- Resources
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Current AssigneeSemiconductor Energy Laboratory Co., Ltd.
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Original AssigneeSemiconductor Energy Laboratory Co., Ltd.
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InventorsSakata, Junichiro, Serikawa, Tadashi
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Primary Examiner(s)Weiss, Howard
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Assistant Examiner(s)SKYLES, TIFNEY L
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Application NumberUS12/639,115Publication NumberTime in Patent Office1,791 DaysField of Search257/43, 257/59, 438/104US Class Current438/104CPC Class CodesH01L 27/1225 with semiconductor material...H01L 29/7869 having a semiconductor body...
