1. Technical Field
The present invention relates to a thin-film device including a thin-film element, such as a thin-film transistor, or other thin-film functional members, and to an electronic apparatus including the thin-film device.
2. Related Art
Thin-film functional members (multilayer composite), such as semiconductor elements, are often formed by a method using a transfer technique. For example, in the techniques disclosed in JP-A-10-125929, JP-A-10-125930 and JP-A-10-125931, a transfer member to be transferred, such as thin-film transistor, is previously formed on a substrate with a release layer therebetween. The transfer member is bound to another target substrate and is then separated from the original substrate by, for example, light irradiation, thereby being transferred. This technique facilitates the formation of a thin-film element or the like on a substrate onto which the thin-film element or the like is not easily formed directly, such as a plastic substrate or a flexible sheet. The transfer technique is useful in forming a plurality of thin-film elements or thin-film circuits that should be formed under different conditions on a substrate. Such thin-film functional members each can be prepared on a substrate under their optimal conditions separately, and then transferred to a target substrate at one time.
When such a transfer technique is applied to the manufacture of a thin-film device, two-step transfer is required to transfer the original layered structure (order of layers) of a thin-film element on a substrate onto a target substrate. More specifically, for example, a thin-film element formed on an original substrate is transferred onto a temporary substrate. The order of layers of the thin-film element is inverted on the temporary substrate at this time. The thin-film element on the temporary substrate is then transferred onto a target substrate. Thus, the resulting thin-film element on the target substrate has the same order of the layers as the thin-film element on the original substrate.
The increase of the number of transfer steps, however, increases the possibility of transfer failure due to stresses and may result in damaged or broken layered structure. On the other hand, a single-step transfer results in an inverted layered structure on the target substrate undesirably. A novel technique is desired to overcome those disadvantages.