Method of fabricating a semiconductor device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Hisashi Ohtani
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Abstract
A semiconductor device with high reliability is provided using an SOI substrate. When the SOI substrate is fabricated by using a technique typified by SIMOX, ELTRAN, or Smart-Cut, a single crystal semiconductor substrate having a main surface (crystal face) of a {110} plane is used. In such an SOI substrate, adhesion between a buried insulating layer as an under layer and a single crystal silicon layer is high, and it becomes possible to realize a semiconductor device with high reliability.
Claims14
A method of fabricating a semiconductor device, said method comprising the steps of:
- preparing a single crystal semiconductor substrate having a main surface of a {110} plane;
- forming an oxide layer in the single semiconductor substrate;
- adding hydrogen into the single semiconductor substrate from a side of the main surface through the oxide layer to form a hydrogen-containing layer in the single crystal semiconductor substrate;
- bonding the single crystal semiconductor substrate and a supporting substrate to each other;
- separating the single crystal semiconductor substrate by a first heat treatment along the hydrogen-containing layer;
- polishing a single crystal semiconductor layer remaining on the supporting substrate and having a main surface of a {110} plane;
- and
- forming an active layer of a thin film transistor by using the single crystal semiconductor layer.
A method of fabricating a semiconductor device, said method comprising the steps of:
- preparing a single crystal semiconductor substrate having a main surface of a {110} plane;
- first oxidizing the single crystal semiconductor substrate to form a porous semiconductor layer;
- carrying out a first heat treatment on the porous semiconductor layer in a reducing atmosphere;
- carrying our an epitaxial growth of a first single crystal semiconductor layer having a main surface of a {110} plane on the porous semiconductor layer;
- second oxidizing the first single crystal semiconductor layer to form an oxide layer, wherein a remaining portion in the first single crystal semiconductor layer which is not oxidized in the second oxidizing step is defined as a second single crystal semiconductor layer;
- bonding the single crystal semiconductor substrate and a supporting substrate to each other;
- polishing the single crystal semiconductor substrate until the porous semiconductor layer is exposed;
- removing the porous semiconductor layer to expose the second single crystal semiconductor layer;
- and
- forming an active layer of a thin film transistor by using the single crystal semiconductor layer over the supporting substrate.
A method of fabricating a semiconductor device, said method comprising the steps of:
- preparing a single crystal semiconductor substrate having a main surface of a {110} plane;
- adding oxygen ions into the single semiconductor substrate from a side of the main surface to form an oxygen-containing layer in the single crystal semiconductor substrate;
- converting the oxygen-containing layer into a buried oxide layer by a heat treatment, wherein a single crystal semiconductor layer having a main surface of a {110} plane remains on the buried oxide layer;
- and
- patterning the single crystal semiconductor layer to form an active layer of a thin film transistor.
Dependencies are inferred from the claim text.