C. Brys

Epitaxial lift-off and its applications

In this paper the authors will give an overview of the epitaxial lift-off (ELO) technique and its applications. This first part will describe the basic technology, which includes chemical lift-off, handling bonding, stress, alignment, etc. The second part will give an overview of device results obtained with ELO (LED and lasers on Si, MESFETs on InP, OEICs etc).

Epitaxial lift-off of ZnSe based II-VI structures

The epitaxial lift‐off technique is applied to II–VI based structures. Epilayers of 255 nm thickness containing quantum wells are lifted off their substrates and redeposited onto polyimide coated GaAs. The technique has also been applied to II–VI samples onto which dielectric films had been deposited. Photoluminescence measurements show that the material quality has not been degraded during the processing. The success of this technique with II–VI’s opens up many possibilities for the integration of these materials with metals and dielectrics in vertical structure devices.

RF and 1/f noise investigations on MESFETs and circuits transplanted by epitaxial lift off

In this paper, we present the results of RF and noise measurements of MESFETs transplanted by epitaxial lift off (ELO). ELO is a technology by which epitaxially grown layers are lifted off from their growth substrate and subsequently reattached to a new host substrate. In the experiments described here a 800 mm thick GaAs film containing MESFETs or complete microwave circuits is transplanted onto semi-insulating InP. Gate leakage current, RF characteristics, and noise performance of MESFETs and GaAs circuits are compared before and after ELO. Special attention was given to low-frequency (1/f) noise, 1/f noise is believed to be caused by surface as well as bulk effects. An increase in 1/f noise could have been predicted since a new surface is exposed during the transplantation process. The mechanical stress during the transplantation could cause crystal damage creating additional traps which could also result in an increase in 1/f noise.

Integrating optical receiver transplanted by epitaxial lift off

A GaAs integrating optical receiver has been designed and realized using a commercial foundry process. The receiver was then transplanted by epitaxial lift off (ELO) onto an InP substrate. This technology allows the monolithical integration of previously incompatible materials onto one chip. To our knowledge the chip described is the most complex chip that has been transplanted by ELO. The integrating receiver described here presents a novel circuit topology to integrate optical input power.

Epitaxially lifted-off GaAs MESFETs on InP for optoelectronic integration

Epitaxial lift-off (ELO) is a technique by which epitaxially grown layers are lifted off their growth substrate and subsequently reattached to a new one. The preprocessing approach where ELO devices and circuits on the host are fabricated before transplantation offers the advantages that (a) fully optimized devices provided by a foundry service can be combined, (b) the devices can be tested prior to transplantation, and (c) the final result is a monolithic integration. The authors present results on the transplantation of foundry MESFETs to InP, and compare their behavior and the extracted parameters for a nonlinear MESFET-model before and after transfer.<<ETX>>