Sputtering target and method for manufacturing semiconductor device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorShunpei Yamazaki
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Abstract
An object is to provide a deposition technique for depositing an oxide semiconductor film. Another object is to provide a method for manufacturing a highly reliable semiconductor element using the oxide semiconductor film. A novel sputtering target obtained by removing an alkali metal, an alkaline earth metal, and hydrogen that are impurities in a sputtering target used for deposition is used, whereby an oxide semiconductor film containing a small amount of those impurities can be deposited.
Claims20
(canceled)
A method for manufacturing a semiconductor device, the method comprising the steps of:
- forming a gate electrode;
- forming a gate insulating layer;
- forming an oxide semiconductor film by a sputtering method using a sputtering target;
- and
- performing a heat treatment on the oxide semiconductor film,
- wherein the heat treatment is performed in an atmosphere containing nitrogen,
- wherein the sputtering target comprises a sintered body comprising zinc oxide and indium oxide,
- wherein the gate electrode and the oxide semiconductor film overlap with each other with the gate insulating layer interposed therebetween,
- wherein the oxide semiconductor film includes crystals with c-axis alignment after the heat treatment, and
- wherein concentration of each of alkali metals contained in the sintered body which is measured by SIMS is 5×1016 cm−3 or lower.
A method for manufacturing a semiconductor device, the method comprising the steps of:
- forming a gate electrode;
- forming a gate insulating layer;
- forming an oxide semiconductor film by a sputtering method using a sputtering target;
- performing a first heat treatment on the oxide semiconductor film;
- forming an oxide insulating film in contact with the oxide semiconductor film;
- and
- performing a second heat treatment on the oxide semiconductor film and the oxide insulating film,
- wherein the sputtering target comprises a sintered body comprising zinc oxide and indium oxide,
- wherein the gate electrode and the oxide semiconductor film overlap with each other with the gate insulating layer interposed therebetween,
- wherein the oxide semiconductor film includes crystals with c-axis alignment after the first heat treatment, and
- wherein concentration of each of alkali metals contained in the sintered body which is measured by SIMS is 5×1016 cm−3 or lower.
A method for manufacturing a semiconductor device, the method comprising the steps of:
- forming a gate electrode;
- forming a gate insulating layer;
- forming a first oxide semiconductor film by a sputtering method using a first sputtering target;
- forming a second oxide semiconductor film over the first oxide semiconductor film by a sputtering method using a second sputtering target;
- and
- performing a heat treatment on the first oxide semiconductor film and the second oxide semiconductor film,
- wherein each of the first sputtering target and the second sputtering target comprises a sintered body comprising zinc oxide and indium oxide,
- wherein the gate electrode and the first oxide semiconductor film overlap with each other with the gate insulating layer interposed therebetween,
- wherein each of the first oxide semiconductor film and the second oxide semiconductor film includes crystals with c-axis alignment after the heat treatment, and
- wherein concentration of each of alkali metals contained in the sintered body which is measured by SIMS is 5×1016 cm−3 or lower.
Dependencies are inferred from the claim text.