Semiconductor device, annealing method, annealing apparatus and display apparatus

Abstract

The semiconductor device according to the present invention has a semiconductor layer having not smaller than two types of crystal grains different in size within a semiconductor circuit on a same substrate.

1 . A semiconductor device having a semiconductor layer comprising not smaller than two types of crystal grains different in average grain diameter in a semiconductor device circuit on a same substrate.  
   
   
       2 . A semiconductor device comprising not smaller than two types of field effect transistors using a semiconductor layer directly or indirectly formed on the substrate as a channel region, wherein, a frequency distribution with respect to ratios of Na/L of the transistors falls within ±5%, where the L is a gate length of the transistor, and the Na is an average number of crystal grain boundaries across the direction of current flowing through the transistor.  
   
   
       3 . The device according to  claim 2 , wherein the frequency distribution with respect to ratios of the Na/L of the transistors falls within ±2%.  
   
   
       4 . The device according to  claim 2 , further comprising a circuit layer on the substrate for driving the transistor.  
   
   
       5 . A thin film transistor for driving a pixel and a pixel drive circuit of a display apparatus, which comprises a pair of substrates joined with a predetermined gap between the pair of substrates and an electro-optical substance held in the gap, a counter electrode formed on one of the pair of substrates, a pixel electrode formed on the other substrate, a crystalline semiconductor thin film electrically connected to the pixel electrode, a pixel drive circuit for driving the pixel, and a crystalline semiconductor thin film formed on the pixel drive circuit, the thin film transistor comprising: 
 (a) inserting a spatial intensity modulating optical element between a laser source and a beam profile measuring section;    controlling gap d 1  between an incident surface of the beam profile measuring section and the spatial intensity modulating optical element at 500 μm or less;    measuring intensity of laser light modulated by the spatial intensity modulating optical element and applied to the incident surface of the beam profile measuring section, distribution of the intensity and the gap d, individually;    (b) inserting the spatial intensity modulating optical element between a substrate having the non single crystalline semiconductor thin film and the laser source, controlling gap d 1  between an incident surface of the substrate and the spatial intensity modulating optical element to 500 m or less, irradiating the incident surface of the substrate with the laser light modulated by the spatial intensity modulating optical element, and measuring the intensity of laser light, distribution of the intensity and the gap d 1  when it is confirmed that lateral crystallization of the semiconductor thin film proceeds by irradiation of the modulated laser light;    (c) setting the measurement results n step (a) corresponding to those in step (b) as target values of the intensity of laser light, distribution of the intensity, and the gap d 1 ;    (d) controlling intensity of laser light, distribution of the intensity and the gap d 1  so as to match with the target values and irradiating the incident surface of the substrate with the laser light modulated by the spatial intensity modulating optical element under the control conditions; and    (e) forming a crystalline semiconductor laser having no smaller than two types of crystal grains different in average diameter in the same substrate by repeating steps (b) and (d) mentioned above.    
   
   
       6 . The thin film transistor according to  claim 5 , which comprises two types of field effect transistors using a semiconductor layer directly or indirectly formed on the substrate as a channel region, and wherein a frequency distribution with respect to ratios of Na/L of the transistors falls within ±5%, where L is a gate length of the transistor, and Na is an average number of crystal grain boundaries across the direction of current flowing through the transistor.  
   
   
       7 . The thin film transistor according to  claim 6 , wherein the frequency distribution with respect to ratios of Na/L of the transistors falls within ±5%.  
   
   
       8 . The thin film transistor according the  claim 6 , which comprises a circuit layer for driving the transistor, which is provided on the substrate.