Optoelectronic semiconductor device with an array of semiconductor diode

Abstract

An array of semiconductor diode lasers (11, 12) is a very suitable radiation source for various applications such as optical read and write systems and laser printers. Such an array includes a semiconductor body (10) with a substrate (1) and a layer structure provided thereon in which at least two lasers (11, 12) are formed which are mutually separated by a groove (20). In the known array, the groove (20) reaches down into the substrate (1), so that the lasers (11, 12) are electrically separated from one another. According to the invention, the array of lasers (11, 12) is provided with a groove (20) with a major portion (d) of its depth (D) which is situated within the substrate (1). As a result of this, the lasers (11, 12) of the array show a surprisingly low crosstalk. Preferably, the portion (d) of the groove (20) situated in the substrate (1) is at least 3 .mu.m deep. The best results are obtained with depths (d) of approximately 10 up to at most 40 .mu.m. In a very favorable embodiment, the device is provided at the upper side with a comparatively thick electrically and thermally conducting layer. In a preferred embodiment, the groove (20) is formed by reactive ion etching so that the groove (20) can be narrow and deep and the lasers (11, 12) will lie close together. A plasma including SiCl.sub.4, Ar and CH.sub.4 forms a particularly suitable etchant for lasers (11, 12) in the InGaP/InAlGaP material system.