An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

At present, a forming process of a base film through an amorphous silicon film is conducted in respective film forming chambers in order to obtain satisfactory films. When continuous formation of the base film through the amorphous silicon film is performed in a single film forming chamber with the above film formation condition, crystallization is not sufficiently attained in a crystallization process. By forming the amorphous silicon film using silane gas diluted with hydrogen, crystallization is sufficiently attained in the crystallization process even with the continuous formation of the base film through the amorphous silicon film in the single film forming chamber.

Method of Manufacturing a Semiconductor Device

A number of studies have demonstrated considerable plasma volume changes during and after exposure to different environmental and physiological conditions. These changes are thought to result from transient fluid shifts into (haemodilution) and out of (haemoconcentration) the intravascular space. If the levels of plasma constituents are to be routinely measured for research purposes or used as indicators of training adaptation or the health of an athlete, then it is important to consider the dynamic nature of plasma volume. Controversy still exists over the relevance of plasma volume interactions with plasma constituent levels, and while some investigators have taken plasma volume shifts into account, others have chosen to ignore these changes. Bouts of acute exercise have been shown to produce a transient haemoconcentration immediately after long distance running, bicycle ergometry and both maximal and submaximal swimming exercise. While these changes are transient, lasting only a few hours, other studies have reported a longer term haemodilution following acute exercise. In addition, endurance training has been shown to cause long term expansion of the plasma volume. It would, therefore, seem important to consider the influence of plasma volume changes on plasma solutes routinely measured for research, and as markers of training adaptation, prior to arriving at conclusions and recommendations based purely on their measured plasma level. To further confound this issue, plasma volume changes are known to be associated with heat acclimatisation, hydration state, physical training and postural changes, all of which may differ from one experiment or exercise bout to the next, and should thus be taken into account.

The influence of exercise-induced plasma volume changes on the interpretation of biochemical parameters used for monitoring exercise, training and sport.

https://openresearch-repository.anu.edu.au/bitstream/1885/40838/3/review1.pdf

A review of thin-film crystalline silicon for solar cell applications. Part 2: Foreign substrates

A method for forming a semiconductor device is disclosed. The method comprises the step of irradiating a laser light to a surface of a semiconductor through a mask provided on said surface in an atmosphere comprising an impurity of one conductivity type to diffuse said impurity into a region of said semiconductor.

Method for forming a semiconductor device

Using an ultrahigh‐vacuum (UHV) sputtering system, we could grow two new methods of polycrystalline silicon films. The one is as‐deposited polycrystalline silicon on glass at substrate temperatures under 500 °C. The other is solid‐phase‐crystallization by thermal annealing of as‐deposited amorphous silicon films in a UHV. As‐deposited polycrystalline silicon films were oriented to (220) and grain sizes were determined from half‐width of x‐ray diffraction to be about 40 nm. From the deposition temperature dependence of the x‐ray diffraction peak intensity, the activation energy of the crystalline growth was calculated to be about 0.6 eV. Hydrogen atoms in the sputtering gas lower the reproducibility of as‐deposited poly‐Si. Polycrystalline silicon films produced by thermal annealing of as‐deposited amorphous silicon films at 550 °C in UHV have a (111) orientation. Field‐effect mobilities of the as‐deposited polycrystalline silicon film and the polycrystalline silicon film by UHV thermal annealing were 5 an...

Polycrystalline silicon formed by ultrahigh‐vacuum sputtering system

We present a new doping technique using an ion shower doping system with a bucket ion source. Phosphorus atoms were implanted in polycrystalline silicon from room temperature to 300 °C. Sheet resistances were significantly reduced by raising the implantation temperature. With a crystal fraction of 85%, sheet resistance was 5×102 S−1/⧠ as implanted. These effects were not due to pure thermal annealing by ion beam heating. A significant improvement was found in sheet resistance as a result of averaging the impurity profile by radiation enhanced diffusion and low temperature recrystallization of the implanted region by collision of atoms.

Implantation temperature effect on polycrystalline silicon by ion shower doping

We investigated the effect of hydrogen ion shower doping on polycrystallinesilicon thin‐film transistors (p‐Si TFTs). Hydrogen atoms were introduced to the channel region of p‐Si TFTs by PH3/H2 ion shower doping of the source/drain contact. Hydrogen concentration in the channel region can be controlled by altering the gate metal thickness. Hydrogen atoms affect the TFT’s threshold voltage shifts until it becomes negative, in n‐type TFTs. The threshold voltage shift depends on the hydrogen content of the channel region in p‐Si TFTs. This is explained by the existence of Si− 3 trap states in the grain boundaries.

N. Matsumoto

Papers

Polycrystalline silicon formed by ultrahigh‐vacuum sputtering system

Implantation temperature effect on polycrystalline silicon by ion shower doping

Effect of hydrogen ion shower doping in polycrystalline silicon thin‐film transistors