Phillipps-Marburg Seminars

When?

Monday 28 March 2011, 16:00

Where?

2ATI02

Open to:

Staff, Students

Speaker:

M Zimprich and S Liebich, Material Science Center and Department of Physics, Philipps University of Marburg, Germany

Monolithic Integration of III/V Laser on Silicon - M Zimprich

The continuous growth in performance of Silicon based CMOS devices leads to the need for fast and energy efficient communication on chip level. To benefit from reduced energy dissipation and higher transmission rates, it is desirable to integrate optical components for data transmission on Silicon (optoelectronic integrated circuit - OEIC). For this application, a monolithically integrated III/V Laser on Silicon would be an ideal source of light. As the lattice parameter of common III/V Laser materials differs strongly from that of Silicon, a defect free pseudomorphic deposition of these materials on Silicon has not been realized.

The novel Ga(NAsP) material system provides a direct band gap material which can be grown lattice matched on Silicon using Metal-Organic Vapor-Phase Epitaxy (MOVPE). Incorporation of Nitrogen offers the possibility to achieve a direct band gap while tuning the lattice parameter to the desired value simultaneously.
The successful demonstration of electrically pumped lasing in Ga(NAsP) structures leads to the conclusion, that this material system has a high potential for the realization of an monolithically integrated laser on Silicon.

Ga(NAsP) laser on Silicon - S Liebich

The pseudomorphic growth of III/V materials on Si is a very challenging task. In particular combining polar III/V and unpolar Si and also their difference in the expansion coefficients gives rise to defects limiting the later device performance.  

Here the metal-organic vapor phase epitaxy (MOVPE) of the novel direct band gap material Ga(NAsP) monolithically integrated on Si will be presented. The compressively-strained Ga(NAsP) quantum wells are embedded within novel Boron containing waveguide and contact layers of (BGa)((As)P). By optimizing the growth parameters the deposition of a laser structure on Si with high crystalline quality and very low defect density is possible. This is validated by several characterization methods e.g. x-ray diffraction and transmission electron microscopy.

Broad area lasers were processed with top p- and n-contacts for lateral current injection.  For the first time lasing at low temperatures is validated. This emphasizes the high potential of this novel gain material for the monolithic integration on Si.