A high-concentration n-type doped thin germanium material on an insulating layer and its manufacturing method

Abstract

The invention discloses a high concentration N type doping thin germanium material on an insulating layer and a manufacture method thereof. The manufacture method of the high concentration N type doping thin germanium material on the insulating layer includes: step 1, placing material; step 2, extending the material; step 3, concentrating germanium. The high concentration N type doping thin germanium material on the insulating layer structurally comprises a silicon substrate, buried layer SiO2 which prevents N type impurity atoms from diffusing towards the silicon substrate, an N type doping thin germanium film and a SiO2 layer, which are sequentially arranged from the bottom up, wherein the thickness of the buried layer SiO2 is larger than or equal to 200nm, the thickness of the N type doping thin germanium film is less than or equal to 30nm, a doping element in the N type doping thin germanium film is phosphorus or arsenic or antimony, and concentration of the doping element is larger than or equal to 1017 / cm<3>. The manufacture method of the high concentration N type doping thin germanium material on the insulating layer mingles impurity atoms in top layer silicon or a germanium and silicon alloy film, and then performs germanium concentration, and thereby improves the N type doping concentration on the one hand, and timely repairs ion injection in a long time oxidizing annealing process or crystal defects generated in an epitaxial growth process on the other hand, and prepares N type doping germanium high in crystal quality.

Description

technical field [0001] The invention belongs to the field of materials, in particular to a high-concentration N-type doped thin germanium material on an insulating layer and a manufacturing method thereof. Background technique [0002] Germanium material has a higher carrier mobility than silicon material, and has a higher absorption coefficient in the optical communication band (1.55μm), which is one of the ideal materials for preparing high-performance microelectronics and optoelectronic devices; at the same time, because germanium The preparation process of the material is compatible with the mature silicon CMOS process, so the application of germanium devices in silicon-based optoelectronic integration has a cost advantage. [0003] Germanium-on-insulator (GOI) material has incomparable advantages over bulk germanium material: on the one hand, the preparation technology of GOI material is to introduce a layer of buried oxide layer between the top germanium and silicon su...

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Problems solved by technology

[0005] At present, there are mainly the following methods for N-type doping in the top layer of Ge thin film: one is by in-situ doping, that is, in the process of epitaxial germanium thin film, doping N-type impurity atoms, which can obtain about 2×10 19 cm -3 N-type doping concentration, but the surface of the material obtained by this method is rough, the activation degree of impurities is low, and the crystal quality is poor, which is not conducive to the improvement of device performance; the second is to increase the N-type doping concentration by ion implantation, but through ion implantation The lattice integrity of germanium is damaged by implanting into the bulk germanium material, and this damage is difficult to be completely repaired by the subsequent annealing process, and this method also has the disadvantages of fast impurity diffusion and serious impurity loss; the third is to use gas immersion laser The doping technology can dope the n-type concentration on the GOI material to 1x10 20 cm -3 The disadvantages of gas immersion laser doping technology are: the integration process is complicated, the technology is not yet mature, the equipment is expensive, and the preparation cost is high

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