Iterative bandgap engineering at selected areas of quantum semiconductor wafers

Abstract

We report on the application of a laser rapid thermal annealing technique for iterative bandgap engineering at selected areas of quantum semiconductor wafers. The approach takes advantage of the quantum well intermixing (QWI) effect for achieving targeted values of the bandgap in a series of small annealing steps. Each QWI step is monitored by collecting a photoluminescence map and, consequently, choosing the annealing strategy of the next step. An array of eight sites, 280 mum in diameter, each emitting at 1480 nm, has been fabricated with a spectral accuracy of better than 2 nm in a standard InGaAs/InGaAsP QW heterostructure that originally emitted at 1550 nm.

Excimer laser induced quantum well intermixing: a reproducibility study of the process for fabrication of photonic integrated devices

“…Thus, the QWI process could deliver multi-bandgap wafers rapidly and, potentially, at an attractive manufacturing cost. Examples of QWI approaches include impurity induced disordering (IID) [12], impurity free vacancy disordering (IFVD) [13], infrared laser annealing [14] [also known as photon absorption induced disordering (PAID)] [15], plasma induced intermixing [16] and ion implantation induced intermixing [17,18]. Among these processes, ultraviolet laser-induced quantum well intermixing (UV-Laser-QWI) is particularly appealing due to its ability to produce selective area bandgap tuned wafers without employing contact masking and associated processing steps.…”