CN103137434B

CN103137434B - The manufacture method of GaN Film on Si Substrate

Info

Publication number: CN103137434B
Application number: CN201110377023.0A
Authority: CN
Inventors: 张帅; 刘坤
Original assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2011-11-23
Filing date: 2011-11-23
Publication date: 2016-02-10
Anticipated expiration: 2031-11-23
Also published as: CN103137434A

Abstract

The invention discloses a kind of manufacture method of GaN Film on Si Substrate, first go out groove at silicon substrate back-etching, then growing GaN film on silicon substrate front, also can first fill in the trench or grow and add strong film, then on silicon substrate front growing GaN film.The manufacture method of GaN Film on Si Substrate of the present invention, because the silicon substrate back side is formed with groove, the intensity of silicon substrate can be reduced, thus when silicon substrate front growing GaN film due to lattice mismatch and thermal mismatching produce stress, can be there is suitable deformation and discharge stress between GaN and silicon substrate in silicon substrate, when reducing silica-based upper large area deposition GaN film, the excessive and GaN film that is that cause silicon substrate front to grow of stress produces the risk of defect or crackle.

Description

The manufacture method of GaN Film on Si Substrate

Technical field

The present invention relates to semiconductor technology, particularly a kind of manufacture method of GaN Film on Si Substrate.

Background technology

GaN semi-conducting material has that forbidden band is wide, thermal conductivity is high, electronics saturation drift velocity is large and the feature such as dielectric constant is little, has a wide range of applications in high brightness LED, short wavelength laser diode, high-performance ultraviolet detector and high temperature, high frequency, large power semiconductor device field.In large-scale industrial production, general use MOCVD (Metal-organicChemicalVaporDeposition, metallo-organic compound chemical gaseous phase deposition) method prepares GaN film on sapphire or silicon carbide substrates, as shown in Figure 1, although these substrates are suitable for preparing high-quality GaN film, but its is expensive, area is little, large area, low-cost production cannot be realized, also incompatible with the silica-based lsi technology of maturation, a difficult problem be it is also proposed to the manufacture of device.

Silicon has the advantages such as good physical performance, quality is high, cost is low, integrated technique is ripe, production scale is large, tempting in the prospect of silicon Epitaxial growth GaN.But there is larger lattice mismatch and coefficient of thermal expansion mismatch between silicon and GaN, thus produce very large stress in epitaxial process, and then induce the defects such as a large amount of dislocations in epitaxial loayer, even cause epitaxial loayer to crack, as shown in Figure 2.People adopt the method release stress such as low temperature buffer layer, epitaxial lateral overgrowth and multi-hole buffer layer usually, although alleviate the mismatch between Si substrate and epitaxial loayer by grown buffer layer, the dislocation density in epitaxial loayer is still very high.We wish to continue to explore other novel methods to discharge the stress in GaN Film on Si Substrate.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of manufacture method of GaN Film on Si Substrate, and the GaN film that can reduce silica-based upper large area deposition produces the risk of defect or crackle.

For solving the problems of the technologies described above, the invention provides a kind of manufacture method of GaN Film on Si Substrate, comprising the following steps:

One. the photoresist of band figure or hard mask is formed at the silicon substrate back side;

Two. utilize the photoresist of band figure or hard mask as etching barrier layer, go out groove at silicon substrate back-etching;

Three. described photoresist or hard mask are removed;

Four. growing GaN film on silicon substrate front.

Also can be that, after step 3, filling or growth add strong film in the trench, and then carry out step 4.

The manufacture method of GaN Film on Si Substrate of the present invention, first deep groove etching method is utilized to form groove at the silicon substrate back side, then growing GaN film on the silicon substrate of band backside trench, because the silicon substrate back side is formed with groove, the intensity of silicon substrate can be reduced, thus when silicon substrate front growing GaN film due to lattice mismatch and thermal mismatching produce stress, suitable deformation can be there is and discharge stress between GaN and silicon substrate in silicon substrate, when reducing silica-based upper large area deposition GaN film, the excessive and GaN film that is that cause silicon substrate front to grow of stress produces the risk of defect or crackle, achieve the low cost GaN Film on Si Substrate adapted with lsi technology to grow.Before the GaN film of growth, in the groove at the back side, the release that any film is beneficial to stress can not be filled, also can add strong film according to subsequent technique process to the various unlike material of requirement Selective filling of silicon chip intensity, so that subsequent technique processing procedure and reduce the risk of fragment.

Accompanying drawing explanation

In order to be illustrated more clearly in the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in the present invention or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 prepares GaN film schematic diagram on sapphire;

Fig. 2 is the manufacture method of conventional GaN Film on Si Substrate, and GaN epitaxial layer cracks schematic diagram;

Fig. 3 is the manufacture method of GaN Film on Si Substrate of the present invention, forms the photoresist of band figure or hard mask schematic diagram at the silicon substrate back side;

Fig. 4 is the manufacture method of GaN Film on Si Substrate of the present invention, etches groove schematic diagram;

Fig. 5 is the manufacture method of GaN Film on Si Substrate of the present invention, and photoresist or hard mask are removed schematic diagram;

Fig. 6 is the manufacture method of GaN Film on Si Substrate of the present invention, fills in the trench or grow to add strong film schematic diagram;

Fig. 7 is the manufacture method of GaN Film on Si Substrate of the present invention, growing GaN film schematic diagram on silicon substrate front;

The bar shaped schematic diagram of Fig. 8 A to be groove shape be periodic arrangement;

The square schematic diagram of Fig. 8 B to be groove shape be periodic arrangement;

The annular schematic diagram of Fig. 8 C to be groove shape be periodic arrangement;

The hexagon schematic diagram of Fig. 8 D to be groove shape be periodic arrangement.

Embodiment

Below in conjunction with the accompanying drawing in the present invention, carry out clear, complete description to the technical scheme in the present invention, obviously, described embodiment is a part of embodiment of the present invention, instead of whole embodiments.Based on the embodiment in the present invention, other embodiments all that those of ordinary skill in the art obtain under the prerequisite not making creative work, all belong to the scope of protection of the invention.

Embodiment one

The manufacture method of GaN Film on Si Substrate, comprises the following steps:

Two. utilize the photoresist of band figure or hard mask as etching barrier layer, utilize the anisotropic of dry etching to etch feature and go out groove at silicon substrate back-etching;

Three. photoresist during ditch groove or hard mask are removed;

Four. growing GaN film on silicon substrate front.

Embodiment two

The manufacture method of GaN Film on Si Substrate, as shown in Fig. 3 ~ Fig. 7, comprises the following steps:

One. form the photoresist of band figure or hard mask 11 at silicon substrate 10 back side, as shown in Figure 3;

Two. utilize the photoresist of band figure or hard mask 11 as etching barrier layer, utilize the anisotropic of dry etching to etch feature and carve groove 12 at the silicon substrate back side, as shown in Figure 4;

Three. photoresist during ditch groove 12 or hard mask 11 are removed, as shown in Figure 5;

Four. fill in groove 12 or the required hardness of growth add strong film 13, as shown in Figure 6;

Five. growing GaN film 14 on silicon substrate front, as shown in Figure 7.

Preferably, the groove 12 bottom corners place etched is arc, and mellow and full channel bottom pattern can avoid the stress concentration effect produced around the corner to damage silicon chip;

The degree of depth of groove 12 needs selected according to Stress Release, the degree of depth of groove 12 can be selected between 1/20 ~ 1/2 of Si-Substrate Thickness;

The shape of groove 12 is varied, as being the bar shaped (as Fig. 8 A) of periodic arrangement, also can be square (as Fig. 8 B) of periodic arrangement, annular (as Fig. 8 C), hexagon (as Fig. 8 D) etc.;

Interval width W1 ~ W4 between the width L1 ~ L4 of each groove 12 and each groove 12 there is no set pattern, can freely change as required, the width L1 ~ L4 of each groove 12 can be equal, also can be unequal, interval width W1 ~ W4 between each groove 12 can be equal, also can be unequal;

The width of groove 12 can be selected between 1um ~ 20um, and the interval width between each groove can be selected between 2um ~ 50um;

That fills in groove 12 adds strong film 13, can be the material such as silicon dioxide, polysilicon, porous silicon used in silicon integrated circuit technique.

Claims

1. a manufacture method for GaN Film on Si Substrate, is characterized in that, comprises the following steps:

Three. described photoresist or hard mask are removed, filling or growth add strong film in the trench;

The described strong film that adds is silicon dioxide, polysilicon or porous silicon;

Four. growing GaN film on silicon substrate front.

2. the manufacture method of GaN Film on Si Substrate according to claim 1, is characterized in that,

In step 2, dry etching is utilized to go out groove.

3. the manufacture method of GaN Film on Si Substrate according to claim 1, is characterized in that,

Trench bottom corner place is arc.

4. the manufacture method of GaN Film on Si Substrate according to claim 1, is characterized in that,

The degree of depth of groove is between 1/20 ~ 1/2 of Si-Substrate Thickness.

5. the manufacture method of GaN Film on Si Substrate according to claim 1, is characterized in that,

The shape of groove is the bar shaped of periodic arrangement, square, annular or hexagon.

6. the manufacture method of GaN Film on Si Substrate according to claim 1, is characterized in that,

The width of each groove is equal or unequal, and the interval width between each groove is equal or unequal.

7. the manufacture method of GaN Film on Si Substrate according to claim 1, is characterized in that,

The width of groove is between 1 μm ~ 20 μm, and the interval width between each groove is between 2 μm ~ 50 μm.