A semiconductor device and a method of manufacture thereof

Abstract

A method of manufacturing a semiconductor device comprises depositing a semiconductor layer over a semiconductor surface having at least one first region with a first (average surface lattice) parameter value and at least one second region having a second parameter value different from the first. The semiconductor layer is deposited to a thickness so self-organised islands form over both the first and second regions. The difference in the parameter value means the islands over the first region have a first average parameter value and the islands over the second region have a second average parameter value different from the first. A capping layer is deposited over islands and has a greater forbidden bandgap than the islands whereby the islands form quantum dots, which have different properties over the first and second regions due to difference(s) between the first and second region islands. The invention also relates to a semiconductor device using the method.

Description

technical field [0001] The invention relates to a semiconductor device including quantum dots, in particular to an optoelectronic semiconductor device including quantum dots and a manufacturing method thereof. The invention can be applied, for example, to light emitting diodes (LEDs) or semiconductor laser diodes. Background technique [0002] Semiconductor optoelectronic devices such as light emitting diodes (LEDs) and laser diodes (LDs) have a wide variety of applications, including as components of indicator lights, as solid state light sources, and in optical storage systems. The suitability of the device for application is determined according to the wavelength of light generated by the device. [0003] The wavelength of light emitted from an optoelectronic device is determined according to the light emitting region of the device, hereinafter referred to as the active region of the device. Typically, semiconductor light emitting devices are fabricated using epitaxial ...

AI Technical Summary

Problems solved by technology

Disadvantages of these vertical stacking methods include: vertically stacked devices with different emission wavelengths are complex and costly, device processing is very complex requiring independent control of currents introduced into devices with different emission wavelengths during operation, and it is necessary to separate grows each active region with an independent emission wavelength

The obvious disadvantage of these methods is that although only one substrate is used, for each individual emission wavelength, epitaxial growth of the entire device structure is required

A significant disadvantage of this selective area epitaxy method is that it relies on direct epitaxial growth onto the mask surface, and thus residual contamination induced at the surface during mask fabrication can degrade the properties of the final quantum dots

Another significant limitation of this method is that the mask is deposited on the substrate surface each time a new SK growth is performed, so this method is not suitable for preparing quantum dot active regions for light-emitting devices where, SK growth of more than one layer is often performed in each device structure so that the emission intensity from the light-emitting device can be high

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