Micro drilled ‘via holes’ in III-V semiconductors

Real-time depth measurement for micro-holes drilled by lasers

An optical system based on the confocal principle has been developed for real-time precision measurements of the depth of micro-holes during the laser drilling process. The capability of the measuring system is theoretically predicted by the Gaussian lens formula and experimentally validated to achieve a sensitivity of 0.5 μm. A nanosecond laser system was used to drill holes, and the hole dept...

Ferromagnetism in (III,Mn)V Semiconductors

Magnetic domains in III-V magnetic semiconductors

Recent progress in the theoretical understanding of magnetic anisotropy and stiffness in III-V magnetic semiconductors is exploited for predictions of magnetic domain characteristics and methods of their tuning. We evaluate the width and the energy of domain walls as well as the period of stripe domains in perpendicular films. The computed stripe width W51.1 mm for Ga0.957Mn0.043As/In0.16Ga0.84...

Ferromagnetism in magnetically doped III-V semiconductors.

The origin of ferromagnetism in semimagnetic III-V materials is discussed. The indirect exchange interaction caused by virtual electron excitations from magnetic impurity acceptor levels to the valence band can explain ferromagnetism in GaAs(Mn) in both degenerate and nondegenerate samples. Formation of ferromagnetic clusters and the percolation picture of phase transition describes well all av...

Composition Fluctuations in Iii-v Semiconductors

Electron microscopy studies have previously revealed the presence of fine scale (lOnm) variations of contrast within III-V compound semiconductor epilayers. Using a pulsed laser atom probe it has been possible to study the microchemistry of these layers at very high resolution. This study has shown that in epilayers of GalnAs, AlInAs and GaAHnAs there are variations of up to 10% in composition....