CN103367117A

CN103367117A - GaN (gallium nitride) substrate production method based on HVPE (hydride vapor phase epitaxy) process

Info

Publication number: CN103367117A
Application number: CN201310282690XA
Authority: CN
Inventors: 朱廷刚
Original assignee: JIANGSU NENGHUA MICROELECTRONIC TECHNOLOGY DEVELOPMENT Co Ltd
Current assignee: JIANGSU NENGHUA MICROELECTRONIC TECHNOLOGY DEVELOPMENT Co Ltd
Priority date: 2013-07-05
Filing date: 2013-07-05
Publication date: 2013-10-23

Abstract

The invention relates to a GaN (gallium nitride) substrate production method based on HVPE (hydride vapor phase epitaxy) process. The method comprises the following steps of (a) growing a GaN epitaxial layer with the thickness of 300 to 350 micrometers on a GaN heterogeneous substrate on the basis of the HVPE process; (b) transversely and longitudinally laser scanning a joint surface of the substrate and the GaN epitaxial layer, and forming a plurality of laser points on the joint surface of the substrate and the GaN epitaxial layer; (c) carrying out the laser stripping on the laser points so as to separate the GaN epitaxial layer from the substrate; and (d) stripping the GaN epitaxial layer stripped surface, and obtaining the GaN substrate for a high-power device or a laser device substrate. Since the GaN epitaxial layer of the needed thickness can be grown in several hours through the HVPE process, compared with the MOCVD (metal organic chemical vapor deposition) process, the time and production cost can be greatly reduced, and the industrialized requirement for utilizing the GaN as the substrate of the high-power device can be met.

Description

A kind of GaN substrate preparation method based on HVPE technique

Technical field

The present invention relates to a kind of GaN substrate preparation method for high-power component or Laser Devices substrate.

Background technology

At present, in making high-power component or semiconductor laser device, normally with GaN as substrate, thereon growing AIN, InGaN or GaN.Wherein, the acquisition of GaN substrate is based on MOVCD(Metal organic chemical vapor Deposition more) technique, i.e. mocvd.Because the GaN substrate thickness as high-power component or semiconductor laser device needs 300um ~ 350um, rely on MOVCD technique to grow into the time that required GaN substrate needs some months, not only consuming time longer, and also cost is higher.

Adopting based on HVPE(Hydride Vapor Phase Epitaxy in order to reduce the rise time and to save cost, also having in the prior art) technique comes growing GaN.Concrete grammar be adopt one such as sapphire as substrate, as shown in Figure 1, it is smooth smooth cuboid.Based on HVPE technique at the long GaN epitaxial loayer of this sapphire substrates.Behind GaN growth 300 ~ 350um, sapphire substrates 1 is integral with GaN knot epitaxial loayer 2, as shown in Figure 2.And because substrate 1 and GaN epitaxial loayer 2 are same material not, the GaN epitaxial loayer 2 that forms of growing belongs to heteroepitaxy, will produce the problem of lattice mismatch.Namely under the effect of tension force, be certain arch between the GaN extension of substrate and generation, namely lattice arches upward.When making high-power component and using as substrate with this GaN, this arch can be brought very large problem, for example locate inaccurate and affect the precision of whole technological process, the parameter of each section will specifically be adjusted, thereby the micro-machined uniformity of wafer is reduced greatly, do not meet industrialization or batch production requirements.

Summary of the invention

The purpose of this invention is to provide a kind of very fast and lower-cost manufacture method based on the GaN substrate of HVPE technique of making for high power semiconductor device of making.

For achieving the above object, the technical solution used in the present invention is: a kind of GaN substrate preparation method based on HVPE technique, and described GaN substrate is used for the substrate as growth high-power component or Laser Devices, and it comprises the steps:

(a), the GaN epitaxial loayer is made step: with the heterogeneous substrate of GaN on grow the GaN epitaxial loayer that thickness is 300um ~ 350um based on HVPE technique;

(b), laser ablation step: described substrate and GaN epitaxial loayer abutted surface are carried out horizontal and vertical laser strafe, form numerous laser spot at both abutted surfaces;

(c), laser lift-off step: described numerous laser spot is carried out laser lift-off, so that described GaN epitaxial loayer is separated with substrate;

(d), polishing step: described GaN epitaxial loayer release surface is denuded processing, thereby to be used for the GaN substrate that high-power component or Laser Devices substrate are used.

Optimally, in the step (a), described substrate is a kind of among SiC, sapphire, the Si.

Further, in the step (b), for substrate and the GaN epitaxial loayer of unlike material, the laser that adopts simultaneously again can be by the another one absorption in substrate or the epitaxial loayer with melting for penetrating the one in substrate or the epitaxial loayer.

When described substrate was sapphire, described laser was that wavelength is less than the laser of 240nm.

In the step (b), described laser is along carrying out horizontal and vertical strafing between adjacent two devices on the GaN epitaxial loayer.

Because technique scheme is used, the present invention compared with prior art has following advantages: the present invention is based on HVPE technique and generate first the GaN epitaxial loayer, then by laser ablation and laser lift-off GaN and its substrate are separated, thereby so that the tension force between GaN and the substrate disappears, the GaN lattice arch that produces because of tension force like this disappears, thus at last with the GaN surface finish so that the GaN that makes can be used as the substrate of follow-up manufacturing high-power component or Laser Devices uses.Because HVPE technique generates the GaN epitaxial loayer of desired thickness and only needs several hours time, greatly saved the time and made cost with respect to MOCVD technique, thereby satisfied the requirement that industrialization is produced.

Description of drawings

Fig. 1 by in the HVPE technique the structural representation of employing substrate;

Fig. 2 is based on the formed substrate of HVPE technique and epitaxial loayer integrative-structure schematic diagram;

Fig. 3 is that the present invention adopts laser to carry out the principle schematic of etching;

Fig. 4 is that the present invention adopts the horizontal and vertical etching of laser to form the principle schematic of stripping area;

Wherein: 1, substrate; 2, GaN epitaxial loayer; 3, laser spot.

Embodiment

The invention will be further described below in conjunction with embodiment shown in the drawings:

GaN substrate preparation method based on HVPE technique provided by the invention, it is at first by HVPE technique growing GaN epitaxial loayer in substrate, then by laser ablation and adopt laser-stripping method that the GaN epitaxial loayer is peeled off from substrate, pass through again polishing, to form required GaN substrate.Concrete steps are as follows:

At first, select a kind of semi-conducting material different from the GaN material as substrate, under the HVPE process conditions, grow the GaN epitaxial loayer in substrate.Because this GaN epitaxial loayer will use as the substrate of lower one semiconductor technology, needs growth thickness at 300um ~ 350um.This technical process needs several hours time to finish.

Because substrate is different from the GaN material, there is tension force between the bi-material combination, so the substrate behind the technological forming and GaN lattice arch upward, integral body is the less arch of radian.

Then, adopt laser that described substrate and GaN epitaxial loayer abutted surface are carried out horizontal and vertical laser and strafe, form numerous laser spot 3 at both abutted surfaces, referring to Fig. 3 and shown in Figure 4.Wherein, the selection of laser should be the one that can penetrate in substrate or the GaN epitaxial loayer, simultaneously again can be by the laser of the another one absorption in substrate or the epitaxial loayer with melting.

Then, above-mentioned numerous laser spot is carried out laser lift-off, and described laser lift-off is to adopt high-octane pulsed excimer laser, according to the size of laser spot, GaN epitaxial loayer and substrate abutted surface are shone, scan one by one to realize that whole GaN epitaxial loayer separates with substrate;

With after substrate separates, lattice tension force between the two disappears at the GaN epitaxial loayer, and GaN returns to nature, and arch disappears.At last, described GaN epitaxial loayer release surface is denuded processing, thereby namely to be used for the GaN substrate that high-power component or Laser Devices substrate are used.

Among the present invention, can select SiC, sapphire or Si based on the base material of HVPE technique, owing to sapphire crystal have cheap cost with and good Lattice Matching degree be widely used in the growth of GaN substrate.Therefore, goodly in the present embodiment select sapphire as substrate, behind the GaN epitaxial loayer that grows 300um ~ 350um in sapphire substrates, adopt wavelength to pass sapphire less than the laser of 240nm from sapphire one side both joint faces are carried out horizontal and vertical irradiation to carry out laser ablation.Because the sapphire substrates band gap is very high, it is transparent for 240nm laser with respect to wavelength, so laser pulse can see through sapphire substrates and get to the GaN layer, and GaN and sapphire junction meeting strong absorption laser energy, so that can be reached about 1000 ℃ by the crystal temperature effect at the laser place of strafing, cause the material production fusing of junction.Owing to adopt the horizontal and vertical multichannel of laser to strafe, thereby formed numerous laser spot.

Equally, the laser that recycles above-mentioned wave band is peeled off laser spot by the laser lift-off system, and is final so that Sapphire Substrate and GaN epitaxial loayer safe separating.At last the GaN epi-layer surface after separating being carried out polishing gets final product.

The method and apparatus such as laser ablation, laser lift-off and polishing related in the above-mentioned steps can be continued to use existing mode, and it is not main points of the present invention, at this its specific implementation is repeated no more.

It is less to adopt method of the present invention to obtain GaN substrate required time, and cost is lower, thereby can realize high power high luminance led chip take GaN as substrate and the industrialization production of laser chip, and cost performance is higher.

Above-described embodiment only is explanation technical conceive of the present invention and characteristics, and its purpose is to allow the personage who is familiar with technique can understand content of the present invention and according to this enforcement, can not limit protection scope of the present invention with this.All equivalences that Spirit Essence is done according to the present invention change or modify, and all should be encompassed within protection scope of the present invention.

Claims

1. GaN substrate preparation method based on HVPE technique, described GaN substrate is used for the substrate as growth high-power component or Laser Devices, and it is characterized in that: it comprises the steps:

2. the GaN substrate preparation method based on HVPE technique according to claim 1 is characterized in that: in the step (a), described substrate is a kind of among SiC, sapphire, the Si.

3. the GaN substrate preparation method based on HVPE technique according to claim 1 and 2, it is characterized in that: in the step (b), substrate and GaN epitaxial loayer for unlike material, the laser that adopts simultaneously again can be by the another one absorption in substrate or the epitaxial loayer with melting for penetrating the one in substrate or the epitaxial loayer.

4. the GaN substrate preparation method based on HVPE technique according to claim 3, it is characterized in that: when described substrate was sapphire, described laser was that wavelength is less than the laser of 240nm.

5. the GaN substrate preparation method based on HVPE technique according to claim 1, it is characterized in that: in the step (b), described laser is along carrying out horizontal and vertical strafing between adjacent two devices on the GaN epitaxial loayer.