Forming method of flash memory unit

[0028] The nanocrystalline silicon particles formed by the existing technology are not uniform, and the number of nanocrystalline silicon particles per unit area is limited.

[0029] The method of forming nanocrystalline silicon particles on the tunneling oxide layer in the existing process is: first form an amorphous silicon layer on the tunneling oxide layer, and perform a seed particle formation process on the amorphous silicon layer, and then perform an annealing process . refer to figure 1 , is a graph showing the relationship between the time for performing the seed grain formation process on the amorphous silicon layer and the density of the seed grains on the amorphous silicon layer. Depend on figure 1 It can be seen that the time t for performing the seed particle formation process is greater than 0 and less than or equal to t 1 (that is, the crystal nucleus incubation period), with the increase of time t, the density of seed crystal particles remains basically unc...