Controllable laser-induced periodic structures at silicon–dioxide/silicon interface by excimer laser irradiation

Abstract

Laser-induced periodical microstructure in a Si substrate covered with a thin layer of silicon dioxide has been studied using KrF excimer laser irradiation for controlling the periodicity. It was found that KrF excimer laser irradiation can produce periodical microstructures in SiO2/Si samples by a single pulse if the laser fluence is large enough when the SiO2 thickness is small. When the SiO2 layer is thick and more than one laser pulse is required, circular patterns can be observed due to the interface defects. The periodicity of the ripple structure linearly depends on the SiO2 thickness. The formation of microstructure does not change the thickness of the SiO2 layer and the crystallinity in the Si substrate. The ripple structure formation in the SiO2/Si structure is related to the thermally generated surface waves. The existence of a SiO2 layer on Si substrate can change the surface tension during the melting of the Si interface and hence control the periodicity of the ripple formation. The lateral periodicity and vertical roughness of the ripple structures are within the range required for laser microtexturing of magnetic recording media.

Nanosecond laser pulse induced concentric surface structures on SiO_2 layer

“…Recently, E. L. Gurevich has reviewed the formation mechanism of fs induced surface structures in detail [8]. The pulsed ns laser induced surface structures have been observed on semiconductors [9][10][11][12][13], metals [9,10,12], and dielectric substrates [14]. The surface structure has close relationship with the thickness of the film and pulse duration, but is independent of the wavelength and fluence of the incident laser [12].…”

“…Under the pulsed laser irradiation, the intrinsic defects or impurities strongly absorb the energy of the incident laser, resulting in locally melting or bending deformation on the surface of substrates. The freezing of surface waves, which are generated on the molten layer, is considered to be the dominant mechanism of the periodic structures formation [11,12].…”

Comparative study of UV radiation hardness of n+p and p+n duo-lateral position sensitive detectors

“…The lattice arrangement in the oxide and/or silicon is also stressed and rearranged, and changes in the interface properties can occur. As more photons get absorbed in the oxide layer, charge species and negatively charged centers are produced that modify the electrical properties of the device [20].…”

Subwavelength ripples adjustment based on electron dynamics control by using shaped ultrafast laser pulse trains

“…Laser-induced periodic surface structures (LIPSS/ripples) have attracted tremendous attention for many years [1][2][3][4][5][6][7][8]. LIPSS can be divided into two distinct types: low spatial frequency LIPSS (LSFL) and high spatial frequency LIPSS (HSFL) [8].…”