Direct Growth Methods for Preparing Diamond-Assisted Heat-Dissipation Silicon Carbide Substrates of GaN-HEMTs

BING DAI

Patent

Atlas literature

Patent

US 11,139,176

Direct Growth Methods for Preparing Diamond-Assisted Heat-Dissipation Silicon Carbide Substrates of GaN-HEMTs

BING DAI

Claims

Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.

1 independent · 9 dependent

1
IndependentSiCCnano-diamond suspensionH₂CH₄diamond-assisted heat-dissipation SiC substrate for GaN-HEMTs
A direct growth method for preparing diamond-assisted heat dissipation silicon carbide substrates of GaN-HEMTs, comprising the steps of; (1) etching holes on a surface of a S i C substrate by laser etching or metal plating etching to obtain a SiC wafer containing a hole structure, wherein the holes are located below the GaN- H EMTs and have a depth of 100 to 400 pm; (2) placing the S i C wafer containing the hole structure sequentially in anhydrous ethanol and deionized water for ultrasonic cleaning to obtain a cleaned SiC wafer containing the hole structure; (3) spin-coating a nano-diamond suspension on a surface of the cleaned SiC wafer containing the hole structure to obtain a S i C wafer with an establishment of an auxiliary nucleation point; (4) placing the SiC wafer with the establishment of the auxiliary nucleation point in an MPCVD device to deposit a diamond layer by introducing hydrogen and methane for 1 to 4 h under a hydrogen ﬂow rate of 100 to 300 s c cm, a methane ﬂow rate of 5 to 30 s cc m, a deposition pressure of 100 to 300 mBar, and a deposition temperature of 700 to 900 0 C to obtain a S i C wafer with a diamond nucleation ﬁlm layer; (5) polishing the SiC wafer with the diamond nucleation ﬁlm layer to remove the diamond nucleation ﬁlm layer on an upper surface while retaining the diamond II nucleation ﬁlm layer in the holes to obtain a SiC wafer with the diamond nucleation ﬁlm layer in the holes; (6) placing the SiC wafer with the diamond nucleation ﬁlm layer in the holes in anhydrous ethanol and deionized water for ultrasonic cleaning to obtain a cleaned SiC wafer with the diamond nucleation ﬁlm layer in the holes; and (7) placing the cleaned SiC wafer with the diamond nucleation ﬁlm layer in the holes in the MPCVD device for deposition only in the holes on the SiC wafer by introducing hydrogen and methane under a hydrogen ﬂow rate of 100 to 300 sc cm, a methane ﬂow rate of 5 to 30 s cc m, a deposition pressure of 100 to 300 mB ar, and a deposition temperature of 700 to 900 0 C until the holes are ﬁlled with the deposition.
1. 2
  Dependent← claim 1
  The direct growth method in claim 1, wherein the holes in step (1) have a length of 100 to 300 m and a width of 100 to 300 m.
2. 3
  Dependent← claim 1
  The direct growth method in claim 1, wherein the SiC wafer containing the hole structure in step (2) is sequentially and ultrasonically cleaned in the anhydrous ethanol for ﬁfteen minutes and the deionized water for ﬁfteen minutes.
3. 4
  Dependent← claim 1nano-diamond suspension
  The direct growth method in claim 1, wherein the nano-diamond suspension in step (3) contains nano-diamond particles sized between 10 to 50 nm.
4. 5
  Dependent← claim 1
  The direct growth method in claim 1, wherein step (3) is replaced by ultrasonic dispersing the cleaned SiC wafer containing the hole structure in a nano-diamond suspension to obtain a SiC wafer with an establishment of an auxiliary nucleation point.
5. 6
  Dependent← claim 1
  The direct growth method in claim 1, wherein, in step (4), hydrogen and methane are introduced for 2 hours under a hydrogen ﬂow rate of 150 s cc m, a methane ﬂow rate of 5 sc cm, a deposition pressure of 150 m B ar, and a deposition temperature of 800 0 C.
6. 7
  Dependent← claim 1
  The direct growth method in claim 1, wherein the polishing in step (5) is a mechanical polishing or a chemically assisted mechanical polishing.
7. 8
  Dependent← claim 1
  The direct growth method in claim 1, wherein the polishing in step (5) is carried out by a polishing disc at a rotation speed of 1000 to 4000 rpm/m in.
8. 9
  Dependent← claim 1
  The direct growth method in claim 1, wherein the SiC wafer having a diamond nucleation ﬁlm layer in the holes in step (6) is sequentially and ultrasonically cleaned in the anhydrous ethanol for twenty minutes and the deionized water for twenty minutes.
9. 10
  Dependent← claim 1
  The direct growth method in claim 1, wherein, in step (7), hydrogen and methane are introduced under a hydrogen ﬂow rate of 150 s cc m, a methane ﬂow rate of 10 s cc m, a deposition pressure of 200 m B ar, and a deposition temperature of 800 0 C.

Worked examples

Embodiments described in the patent, grouped by the materials and process steps they use.

Embodiment (paragraphs 0031-0035)

description derived process summary

3 materials2 process steps

Holes etched on SiC substrate surface by metal plating etching with length 100 µm, width 300 µm, depth 180 µm; ultrasonic cleaning in ethanol and deionized water for 15 minutes each; ultrasonic dispersion in nano-diamond suspension (30 nm particle size) for 30 minutes to establish auxiliary nucleation points; MPCVD deposition of diamond nucleation film layer for 2 hours.

Device structures

Layer stacks claimed or described, ordered top of device to substrate.

diamond-assisted heat-dissipation SiC substrate for GaN-HEMTs

GaNdevice layer

Cheat dissipation fill in holes

SiCsubstrate

Materials

Materials described outside the worked examples.

hydrogen

H₂

Process Gas

methane

CH₄

Process steps

Additional fabrication and treatment steps described in the patent.

Mpcvd Growth

Step 1

Temperature

800°C

Duration

120 min

Ambient

H2/CH4

Process details

Reported properties

Performance values and ranges asserted in the specification or claims.

Property	Value	Material
Thermal Conductivity	2200 W/(m·K)	C
Thermal Conductivity

Why these are connected

Related documents with shared materials, methods, properties, or citations.

Direct Growth Methods for Preparing Diamond-Assisted Heat-Dissipation Silicon Carbide Substrates of GaN-HEMTs | Matter42 Literature