CN104319233B

CN104319233B - InN/LT AlN combined stresses discharge buffer layer technique in a kind of MOCVD

Info

Publication number: CN104319233B
Application number: CN201410520437.8A
Authority: CN
Inventors: 罗睿宏; 张国义
Original assignee: Sino Nitride Semiconductor Co Ltd
Current assignee: Sino Nitride Semiconductor Co Ltd
Priority date: 2014-09-30
Filing date: 2014-09-30
Publication date: 2018-03-13
Anticipated expiration: 2034-09-30
Also published as: CN104319233A

Abstract

The present invention provides a kind of InN/LT AlN combined stresses release buffer layer technique used in MOCVD boards.Stress release layer is a kind of critical function layer in MOCVD Material growths, good stress release effect can be realized, improve the angularity and crystal mass of epitaxial wafer, especially seem especially important in this dissimilar materials epitaxial growths that huge thermal mismatching and lattice mismatch be present of GaN On Silicon.The invention provides InN/LT AlN combined stresses to discharge buffer layer technique, one layer of InN functional layer is first deposited before LT AlN (low temperature nitride aluminium) buffer growth, so as to form combined stress release cushion, so as to discharge the stress brought in Heteroepitaxy well.

Description

InN/LT-AlN combined stresses discharge buffer layer technique in a kind of MOCVD

Technical field

The invention belongs to semi-conducting material manufacturing field, be related in the semiconductor devices epitaxial growth of high quality it is compound should Power discharges buffer layer technique.

Background technology

Because substrate (Si, sapphire, carborundum etc.) from GaN epitaxial layer has different lattice mismatches and thermal coefficient of expansion, After growth internal stress can be produced in epitaxial layer.In some fields, the stress field in epitaxial layer influences or restricted to some extent The performance of device.The stress field of hetero-epitaxy turns into one of puzzlement problem of semiconductor applications.At present, scientific researcher passes through Different approach carries out stress release, also achieves breakthrough progress.Including super-lattice buffer layer technology, gradual change AlGaN delays Layer technology, gradient AlGaN buffer layer techniques, LT-AlN (low temperature nitride aluminium) buffer layer technique etc. are rushed, these technologies have each Advantage and disadvantage, wherein LT-AlN cushions are a kind of technologies for efficiently eliminating stress field, while it is also obstructed to a certain extent Dislocation improves crystal mass.But its improvement to epitaxial wafer angularity is but without obvious effect.

The content of the invention

The present invention provides InN/LT-AlN combined stresses release buffer layer technique in a kind of MOCVD,.Its principle is, In MOCVD heteroepitaxial growths, one layer or multilayer InN/LT-AlN combined stress release cushion is inserted, utilizes InN layer sheets Body material property, improves the stress release effect of single LT-AlN cushions, and strengthens its control of angularity to epitaxial layer Ability.MOCVD epitaxy grows hetero-epitaxy, the growing gallium nitride extension especially on silicon, be unable to do without the functional layer that stress is adjusted.This Invention is grown using InN material at low temperature, easily decomposes the characteristic reunited at high temperature, coordinates the high-temperature stable of AlN materials, high leaching Moisten characteristic, be combined into the stress regulatory function layer of high quality, so as to discharge stress caused by dissimilar materials growth, completion is high-quality The Epitaxial gallium nitride layer growth of amount, low-stress state or even unstress state.It should be noted that MOCVD of the present invention is heterogeneous outer In epitaxial growth, InN/LT-AlN combined stresses release buffer layer technique, its InN/LT-AlN combined stress release cushion is set Put, can be one layer or multilayer.

Brief description of the drawings

Fig. 1 is the standard InN/LT-AlN combined stresses release cushion schematic diagram of the present invention

Fig. 2-1 is the embodiment of the present invention 1, and the InN/LT-AlN combined stresses that bottom is GaN discharge cushion schematic diagram

Fig. 2-2 is the embodiment of the present invention 2, and the InN/LT-AlN combined stresses that bottom is AlGaN discharge cushion schematic diagram

Fig. 2-3 is the embodiment of the present invention 3, and bottom is that multilayer InN/LT-AlN combined stresses discharge cushion schematic diagram

Embodiment

InN/LT-AlN combined stresses release buffer layer technique, the reality of its epitaxial growth scheme in a kind of MOCVD of the present invention It is as follows to apply process：

1. using buffer layer technique in MOCVD, on foreign substrate such as sapphire, silicon chip, carborundum etc., one layer is grown Gallium nitride film.

2. between temperature is reduced into 500 DEG C -800 DEG C, grow the thick InN thin layers of one layer of 2-20nm.

3. then, by temperature be transferred to 50 DEG C of the InN growth temperatures temperature difference or within, grow the thick AlN layers of one layer of 5-20nm Film.

4. after growing AIN film, stop growing 0-20s, then raises temperature growth gallium nitride layer.

5. as needed, in MOCVD heteroepitaxial growths, its InN/LT-AlN combined stress release cushion can be with One layer or multilayer are set, and it grows, and can carry out once or repeatedly.

As shown in figure 1, discharging cushion schematic diagram for the InN/LT-AlN combined stresses of standard, 1 is backing material, can be Sapphire, silicon, carborundum etc.；2 be cushion；3 be lower floor GaN；4 be InN layers；5 be LT-AlN layers；6 be upper strata GaN.

By the present invention, buffer layer technique is discharged using InN/LT-AlN combined stresses, it is possible to achieve significantly reduce nitrogen Change growth stress of the gallium based material in foreign substrate, and the angularity of controllable gallium nitride material epitaxial layer.So as to be heterogeneous Material growth gallium nitride prepares device and provides preferably basis.

Embodiment 1.

It is the epitaxial growth scheme that bottom is GaN as shown in Fig. 2-1,1 is substrate material layer, can be sapphire, silicon, carbon SiClx etc.；2 be cushion；3 be lower floor's GaN layer；4 be InN layers；5 be LT-AlN layers；6 be upper strata GaN layer；7 be functional layer, can For quantum well structure, two-dimensional electron gas structure etc..

Embodiment 2.

It is the epitaxial growth scheme that bottom is AlGaN as shown in Fig. 2-2,1 is substrate material layer, can be sapphire, silicon, Carborundum etc.；2 be cushion；3 be lower floor's AlGaN layer；4 be InN layers；5 be LT-AlN layers；6 be upper strata GaN layer；7 be function Layer, can be quantum well structure, two-dimensional electron gas structure etc..

Embodiment 3.

As Figure 2-3, it is that bottom buffers layer epitaxially grown scheme for the release of multilayer InN/LT-AlN combined stresses, 1 is Substrate material layer, can be sapphire, silicon, carborundum etc.；2 be cushion；3 be lower floor AlGaN or GaN layer；4 be InN layers；5 are LT-AlN layers；6 be middle level GaN layer；7 be InN layers；8 be LT-AlN layers；9 be upper strata GaN layer；10 be functional layer, can be SQW Structure, two-dimensional electron gas structure etc..

Claims

1. the growing method of InN/LT-AlN combined stresses release cushion in a kind of MOCVD, it is characterised in that different in MOCVD In matter epitaxial growth, insertion InN/LT-AlN combined stress release cushions；

The growth temperature of the InN layer materials is 500 DEG C to 800 DEG C；

The combined stress discharges cushion, and its InN layer and the growth temperature difference of LT-AlN material layers are less than 50 DEG C；

After the combined stress release buffer growth, stop growing the 0-20s times, then raise temperature growth gallium nitride layer.