Forming method for semiconductor thin film and forming device for semiconductor thin film

Abstract

A method for forming a semiconductor film with good crystallinity on a base layer made of an insulating material and a device for forming the semiconductor film. The forming device of this semiconductor film comprises: an excimer laser (excimer laser) 1 as a light source; a homogenizer (homogenizer) 3 that uniformly distributes the light intensity of the light emitted from the excimer laser 1; An amplitude modulation photomask 5 that distributes the amplitude of the light homogenized by the homogenizer 3 in such a way that the relative motion direction of the light relative to the amorphous substrate 9 increases; the amplitude is modulated by the amplitude modulation shield 5 The light that has been modulated is projected onto the projection optical system 6 formed on the non-single crystal semiconductor layer 10 formed on the amorphous substrate 9 in such a manner that a predetermined irradiation energy can be obtained; A light phase shifter (phase shifter) 8 for the light intensity at the starting point of growth; and a substrate table that moves the light and the amorphous substrate 9 relative to each other to scan in the X and Y directions.

Description

technical field [0001] The invention relates to a method for forming a semiconductor thin film on a base layer made of insulating materials and a device for forming the semiconductor thin film. Background technique [0002] The formation method of existing semiconductor thin film is to use the base layer that insulating material is formed, such as amorphous substrate, especially cheap glass substrate, in order to form semiconductor thin film (such as silicon (Si) with good crystallinity on this substrate Thin film), using the crystallization method of ultraviolet (UV) pulse laser to polycrystallize the semiconductor thin film. [0003] However, the current silicon thin film obtained by the practical laser crystallization technology has a polycrystalline thin film with an average crystal grain size of several hundred nanometers (nm), and its mobility (mobility) is affected by the crystal grain boundary at most by only 200 cm. 2 / V sec. [0004] For thin film transistors (TF...

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Problems solved by technology

[0016] 1) In principle, if the conveying pitch exceeds the length of the SLG (up to 1 μm), step and repeat operations (step and repeat) cannot be performed, so its productivity is poor

[0017] 2) The mobility of the polycrystalline film obtained by this method has its limit

The polycrystalline thin film obtained by increasing the grain size without controlling the position of the grain boundary is not practical because the grain size is quite non-uniform.

[0018] 3) In the scanning direction, there are residual crystal grain boundaries almost every hundreds of nm, and in the direction perpendicular to the scanning direction, there are also crystal defects at every conveying pitch, so it can be seen from the film with a channel length of 1 μm From the perspective of applicability on transistors, it is not suitable for the current situation

[0031] Therefore, there are problems in the positional accuracy and high density in the crystallization field, and it is necessary to make a trade-off between the uniformity in the laser irradiation field and the irradiation area, and there will be problems in productivity in practical use.

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