Semiconductor device including a thin film transistor and a capacitor
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorAkira Ishikawa
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Abstract
A semiconductor device and a method for preparing the same that can solve crack of a semiconductor film, capacitance electrodes and the like due to stress when forming a source electrode and a drain electrode in a semiconductor device having a thin film transistor and a holding capacitance with three or more capacitance electrodes is provided. Before forming the source electrode and the drain electrode, a crystalline silicon film for relaxing the stress is formed, then a contact hole connecting to the semiconductor film of the thin film transistor is opened, and a metal film to be the source electrode and the drain electrode is formed.
Claims16
A semiconductor device comprising:
- a first shielding film;
- a thin film transistor over the first shielding film, the thin film transistor comprising a gate electrode, a source electrode, and a drain electrode;
- a capacitor element comprising a first electrode, a second electrode and a third electrode;
- a second shielding film overlapping with the capacitor element;
- and
- a pixel electrode over the second shielding film, the pixel electrode overlapping with the capacitor element,
- wherein each of the source electrode and the drain electrode overlaps with the gate electrode,
- wherein the second shielding film is arranged in a reticulation pattern,
- wherein the first electrode is formed from a first conductive layer, and
- wherein the first conductive layer comprises a semiconductor film doped with an impurity element,
- wherein the source electrode and the drain electrode are formed from a second conductive layer,
- wherein the second electrode is formed from the second conductive layer, and
- wherein each of the gate electrode and the third electrode is formed from a third conductive layer.
A semiconductor device comprising:
- a first shielding film;
- a thin film transistor over the first shielding film, the thin film transistor comprising a gate electrode, a source electrode, and a drain electrode;
- a capacitor element comprising a first electrode, a second electrode and a third electrode;
- a second shielding film overlapping with the capacitor element;
- and
- a pixel electrode over the second shielding film, the pixel electrode overlapping with the capacitor element,
- wherein the first electrode is formed from a first conductive layer, and
- wherein the first conductive layer comprises a semiconductor film doped with an impurity element,
- wherein the source electrode and the drain electrode are formed from a second conductive layer,
- wherein the second electrode is formed from the second conductive layer, and
- wherein each of the gate electrode and the third electrode is formed from a third conductive layer.
Dependencies are inferred from the claim text.