Semiconductor thin film and its manufacturing method and semiconductor device and its manufacturing method
View Patent ↗A semiconductor thin film is formed having a lateral growth region which is a collection of columnar or needle-like crystals extending generally parallel with a substrate. The semiconductor thin film is illuminated with laser light or strong light having equivalent energy. As a result, adjacent columnar or needle-like crystals are joined together to form a region having substantially no grain boundaries, i.e., a monodomain region which can substantially be regarded as a single crystal. A semiconductor device is formed by using the monodomain region as an active layer.
1. A semiconductor device having at least a static random access memory, the static random access memory comprising:
a word line over a substrate;
a bit line intersecting perpendicularly to the word line, over the substrate; and
at least a first thin film transistor and a second thin film transistor over the substrate;
wherein a gate electrode of the first thin film transistor is connected to a source or drain region of the second thin film transistor,
wherein a gate electrode of the second thin film transistor is connected to a source or drain region of the first thin film transistor, and electrically connected to the bit line,
each of the first and second thin film transistors comprising:
a crystalline semiconductor film comprising silicon on an insulating film,
wherein the insulating film has at least one asperity of less than 30 Å in height on the upper surface thereof.
2. A semiconductor device having at least a static random access memory according to claim 1 , wherein the static random access memory further comprising:
a first resistor connected to a source or drain region of the first thin film transistor;
a second resistor connected to a source or drain region of the second thin film transistor.
3. A semiconductor device having at least a static random access memory according to claim 1 , wherein the static random access memory further comprising:
a third thin film transistor provided between a source or drain region of the first thin film transistor and the bit line; and
a fourth thin film transistor provided between a source or drain region of the second thin film transistor and the word line,
wherein gate electrodes of the third and fourth thin film transistor are connected to the word line.
4. A semiconductor device having at least a static random access memory according to claim 1 , wherein the insulating film comprises silicon oxide.
5. A semiconductor device having at least a static random access memory according to claim 1 , wherein the asperity has a width more than 100 Å.
6. A static random access memory according to claim 1 , wherein crystals of the crystalline semiconductor film extend in parallel with the substrate.
7. An electronic appliance comprising the semiconductor device having at least a static random access memory according to claim 1 , wherein the electronic appliance is selected from the group consisting of a TV camera, a head-mount display, a car navigation, a projection display, a video camera, a personal computer, and a cellular telephone.