Method for improving the efficiency of epitaxially produced quantum dot semiconductor components

• US 6,942,731 B2
• Filed: 08/30/2001
• Issued: 09/13/2005
• Est. Priority Date: 08/30/2000
• Status: Expired due to Term

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Technische Universitã¤T Berlin (Tu)
• Inventors: Sellin, Roman, Ledenstov, Nikolai N., Bimberg, Dieter
• Primary Examiner(s): KUNEMUND, ROBERT M
• Application Number:
  US10/363,031
• Publication Number:
  US 20040020424A1
• Time in Patent Office: 1,475 Days
• Field of Search: 117/89, 117/90, 117/94, 117/95, 117/101, 117/102, 117/104
• US Class Current: 117/89
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 21/02543 Phosphides
• CPC Class Codes: H01L 21/02546 Arsenides
• CPC Class Codes: H01L 21/02617 Deposition types
• CPC Class Codes: H01L 29/127 Quantum box structures
• CPC Class Codes: H01L 31/03046 including ternary or quaternary compounds, e.g. GaAlAs, InGaAs, InGaAsP
• CPC Class Codes: H01L 31/035236 Superlattices; Multiple quantum well structures
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01S 5/3412 quantum box or quantum dash
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials

Abstract

The invention relates to a method for improving the efficiency of epitaxially grown quantum dot semiconductor components having at least one quantum dot layer. The efficiency of semiconductor components containing an active medium consisting of quantum dots is often significantly below the theoretically possible values. The inventive method enables the efficiency of the relevant component to be clearly increased without substantially changing the growth parameters of the various epitaxial layers. In order to improve the efficiency of the component, the crystal is morphologically changed when the growth of the component is interrupted at the point in the overall process at which the quantum dots of a layer have just been covered. The growth front is smoothed at the same time, leading to, for example, a reduction in waveguide loss as the thickness of the waveguide is more homogeneous if the relevant component has one such waveguide. Simultaneously, smoothing the growth front enables the quantum dot layers to be stacked closer together than before, thereby increasing the volume filling factor. The modal gain is thus increased, for example for lasers or amplifiers.

Claims

1. A method for improving the efficiency of epitaxially produced quantum dot semiconductor components having at least one quantum dot layer, comprising the step of interrupting growth of the semiconductor component each time after a layer of coherent quantum dots has been overgrown with a layer of semiconductor material at least thick enough to completely cover all the quantum dots, wherein the step of interrupting growth of the semiconductor component is carried out for each quantum dot layer.

2. Method according to claim 1, characterized in that the substrate temperature during the growth interruption is higher than the temperature at which the quantum dot material was deposited.

3. Method according to claim 1, characterized in that the semiconductor component is an optoelectronic component.

4. Method according to claim 1, characterized in that the semiconductor component contains a waveguide.

5. Method according to claim 1, characterized in that the semiconductor component is a laser.

6. Method according to claim 1, characterized in that the semiconductor component is an amplifier.

7. Method according to claim 1, characterized in that the semiconductor component is a modulator.

8. Method according to claim 1, characterized in that semiconductor component is a photodetector.

9. Method according to claim 1, characterized in that the growth front is smoothed during the growth interruption.

10. Method according to claim 1, characterized in that the waveguide losses are reduced.

11. Method according to claim 1, characterized in that in the case of a multiple stack of quantum dot layers, a subsequent QD layer is deposited immediately after the growth interruption described in claim 1.

12. Method according to claim 11, characterized in that the surface density of QD of a following layer is no smaller than the QD density in the preceding QD layer due to the formation of completely relaxed clusters of dislocations.