Device for thermal conduction and electrical isolation
The disclosure provides an insulated metal substrate (IMS) including a substrate having a first side and a second side. The IMS may also include a first dielectric layer on the first side of the substrate. The dielectric layer may include a metal-based oxynitride and/or a metalloid-based oxynitride layer, oxygen is from 0.1 at % to 49.9 at %, nitrogen is from 0.1 at % to 49.9 at % and a sum of oxygen and nitrogen is about 50 at %. The first dielectric layer comprises a material selected from a group consisting of aluminum oxynitride (AlON), aluminum oxyhydronitride (AlHON), aluminum oxycarbonitride (AlCON), SiGeON, GaON, SiON, and GeON. The substrate comprises one of Cu, Al, AlSi, C—Al, W—Cu, or Ti.
1 . A method for forming an insulated metal substrate with a metal rich surface, the method comprising:
cleaning a copper (Cu) substrate;
lapping the Cu substrate;
electropolishing the Cu substrate;
forming a 10 μm aluminum oxynitride (AlON) layer on the Cu substrate;
forming a 0.05 μm Cu rich AlON layer on the 10 μm AlON layer;
laser etching a 0.05 μm deep pattern; and
etching to remove excess Al.
2 . The method of claim 1 , the method further comprising:
electrolytically depositing a Cu layer;
depositing an additional seed layer;
electrolytically depositing a palladium layer; and
applying an immersion gold layer.
3 . The method of claim 2 , further comprising electrolytically depositing a Cu layer;
depositing an additional seed layer; electrolytically depositing a palladium layer; and applying an immersion gold layer.
4 . The method of claim 1 , the aluminum oxynitride dielectric layer has a thickness between 5 μm and 50 μm on the copper substrate.
5 . The method of claim 1 , wherein the insulated metal substrate produced by the method exhibits a breakdown strength greater than 50 V/μm.
6 . The method of claim 1 , wherein the aluminum oxynitride layer formed on the Cu substrate has a thickness between 5 μm and 20 μm.
7 . The method of claim 1 , wherein the aluminum oxynitride layer formed on the Cu substrate has a thickness between 1 μm and 100 μm.
8 . The method of claim 1 , wherein the aluminum oxynitride layer is configured to provide electrical isolation while maintaining thermal conduction across the substrate.
9 . The method of claim 1 , wherein the Cu rich ALON layer has a thickness up to 0.05 μm.
10 . The method of claim 1 , wherein the copper-rich aluminum oxynitride layer transition from a region devoid of copper to at least one region comprising copper.
11 . The method of claim 1 , wherein the insulated metal substrate has a compositionally graded interface extending from an aluminum oxynitride layer to a copper region, the interface comprising a copper-rich aluminum oxynitride region.
12 . The method of claim 1 , wherein copper concentration increases across a thickness from the aluminum oxynitride layer toward the copper substrate.
13 . The method of claim 1 , wherein the copper-rich aluminum oxynitride layer adjoins a metallic copper region.
14 . The method of claim 1 , wherein laser etching removes material without etching through the entire thickness of the layer.
15 . The method of claim 1 , wherein laser etching is performed on selected regions of the aluminum oxynitride layer to define a pattern.
16 . The method of claim 1 , wherein etching reduces aluminum concentration without completely removing aluminum from the copper-rich aluminum oxynitride layer.
17 . The method of claim 1 , further comprising depositing a copper layer and a palladium layer by an electroless deposition process.
18 . The method of claim 1 , further comprising depositing a copper layer by electroless deposition, depositing a palladium layer by electroless deposition, and applying an immersion gold layer.
19 . The method of claim 1 , further comprising depositing at least one of a copper layer or a palladium layer by an electroless deposition process.
20 . The method of claim 1 , wherein the copper layer is deposited by one of electrolytic deposition or electroless deposition.
21 . The method of claim 1 , wherein the laser etching defines a patterned structure comprising electrically isolated regions.
22 . The method of claim 1 , wherein the laser etching selectively removes material from discrete regions of the aluminum oxynitride layer.
23 . The method of claim 1 , further comprising chemically etching the aluminum oxynitride layer.
24 . The method of claim 1 , etching to remove excess Al comprises by chemical etching to further define patterned regions.
25 . The method of claim 1 , wherein etching to remove excess Al comprises chemical etching.
26 . The method of claim 1 , wherein the patterned structure defines conductive features within the insulated metal substrate.
27 . The method of claim 1 , further comprising etching a subsequently deposited metal layer.
28 . The method of claim 1 , wherein patterned metallization features are formed on the insulated metal substrate.
29 . A method for forming an insulated metal substrate with a metal rich surface, the method comprising:
cleaning a copper (Cu) substrate;
lapping the Cu substrate;
electropolishing the Cu substrate;
forming an aluminum oxynitride (AlON) layer of less than 200 μm on the Cu substrate; and,
forming a Cu rich AlON layer on the AlON layer.
30 . The method of claim 29 further comprising:
laser etching a pattern having a depth of at least 0.05 μm; and
etching to remove excess Al.