Cu—Ga—In—Na target

Abstract

A sputtering target is composed of an alloy consisting of 5 to 70 at % of at least one element from the group of (Ga, In) and 0.1 to 15 at % of Na, the remainder being Cu and typical impurities. The sputtering target includes at least one intermetallic Na-containing phase.

Claims

1. A sputtering target, comprising an alloy consisting of 5 to 70 at % of at least one element selected from the group consisting of Ga and In, and 0.1 to 15 at % of Na, and a remainder Cu and impurities, and the sputtering target containing at least one Na-containing intermetallic phase.

2. The sputtering target according to claim 1, wherein said at least one Na-containing intermetallic phase is selected from the group consisting of the intermetallic GaNa phases, the intermetallic In-Na phases and the intermetallic GaInNa phases.

3. The sputtering target according to claim 1, wherein said at least one Na-containing intermetallic phase is selected from the group consisting of NaGa.sub.4, Na.sub.5Ga.sub.8, Na.sub.7Ga.sub.13, Na.sub.22Ga.sub.39, Naln, Na.sub.2In, Na.sub.7In.sub.12, Na.sub.15In.sub.27 and Na.sub.17Ga.sub.29In.sub.12.

4. The sputtering target according to claim 1, wherein said Na-containing intermetallic phase is present embedded in homogeneous distribution in a matrix of at least one element selected from the group consisting of Cu, Ga and In.

5. The sputtering target according to claim 1, wherein said remainder Cu amounts to more than 30 at % of Cu.

6. The sputtering target according to claim 1, wherein a content of said at least one element selected from the group consisting of Ga and In amounts to between 20 and 65 at %.

7. The sputtering target according to claim 1, wherein a ratio in at % of the constituents Ga/(Ga+In) lies between 0.15 and 0.35.

8. The sputtering target according to claim 1, containing between 1 and 5 at % Na.

9. The sputtering target according to claim 1, wherein the sputtering target is formed as a plate, a disc, a rod, a tube, or a body of complex shape.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING:

(1) FIG. 1 is a phase diagram of the Ga-Na system [ASM Phase Diagrams Center, Diagram No. 103346]; compositions of the preliminary alloy powders of Examples 1 to 5 marked.

(2) FIG. 2 is a phase diagram of the In-Na system [ASM Phase Diagrams Center, Diagram No. 903718]; compositions of the preliminary alloy powders of Examples 6 and 7 marked.

(3) FIG. 3 is an X-ray diffractogram for Example 3, JCPDS cards used for Ga Number 03-065-2492, for Ga.sub.4N Number 00-043-1375.

WORKING EXAMPLES

(4) The working examples are summarized in Table 1.

(5) TABLE-US-00001 TABLE 1 Example Cu Ga In [at %] Na Powder route Compaction Form/target 1 72 27 0 1 Ga/Na 75/25, melting at Uniaxial hot press, Disc, 5 mm, 200 C., casting at 600 C., 400 C. 100 mm ingot; Cu/Ga powder 75/25 2 64 31 0 5 Ga/Na 65/35, melting at Degas can at Tube, 200 C., casting at 600 C., 300 C., HIP at 155/135 ingot; Cu/Ga powder 75/25 450 C. and 250 mm 100 MPa 3 68 31 0 1 Ga/Na 65/35, melting at SPS hot press Disc, 5 mm, 200 C., atomizing at 600 C., 400 C. 100 mm Cu/Ga powder 70/30 4 40 15 40 5 Ga/Na 75/25, melting at CIP Disc, 5 mm, 200 C., casting at 600 C., 100 mm ingot; Cu/In powder 50/50 5 73 26 0 1 Ga/Na 65/35, melting at Degas can at Cylindrical, 200 C., casting at 600 C., 300 C., HIP at 10 50 mm ingot; Cu/Ga powder 75/25 450 C. and extrusion press, 100 MPa 100 mm two-part disc 6 78 0 21 1 In/Na 55/45, melting at Uniaxial hot press, Disc, 5 mm, 300 C., casting at 500 C., 400 C. 100 mm ingot; Cu/In powder 80/20 7 64 0 31 5 In/Na 40/60, melting at Evacuate, HIP at Tube, 300 C., atomizing at 400 C. and 155/135 500 C.; Cu/In powder 70/30 100 MPa 250 mm 8 41 17 37 5 Ga/In/Na 50/20/30, melting SPS hot press Disc, 5 mm, at 250 C., casting at 550 C.; 400 C. 100 mm ingot; Cu/In/Ga powder 9 42 8 45 5 Ga/In/Na 50/20/30, melting Evacuate, HIP at Tube, at 250 C., casting at 550 C.; 450 C. and 155/135 ingot; Cu/In powder 50/50 100 MPa 250 mm

Example 1

(6) 1 kg of Ga were heated to 200 C. and melted in a graphite crucible by means of induction heating. Subsequently, 0.1 kg of Na was added (ratio in at % Ga/Na=75/25). The temperature was subsequently increased to 600 C. After complete melting, the alloy was cast in a die made from hot-work steel.

(7) After solidification, the ingot thus produced was removed and, after complete cooling, comminuted with the aid of a jaw crusher and a cross-beater mill.

(8) Thereafter, the GaNa preliminary alloy powder thus obtained was screened off to a size of <500 m and mixed with gas-atomized CuGa alloy powder (Ga content 25 at %), such that an Na content of 1 at % was established.

(9) The CuGaNa powder mixture thus obtained was compacted to a disc in a uniaxial hot press at a temperature of 400 C. and then processed to completion to give a sputtering target having a thickness of 5 mm and a diameter of 100 mm.

Example 2

(10) 5 kg of Ga were heated to 200 C. and melted in a graphite crucible by means of induction heating. Subsequently, 0.9 kg of Na was added (ratio in at % Ga/Na=65/35). The temperature was subsequently increased to 600 C. After complete melting, the alloy was cast in a die made from hot-work steel.

(11) After solidification, the ingot thus produced was removed and, after complete cooling, comminuted with the aid of a jaw crusher and a cross-beater mill.

(12) Thereafter, the GaNa preliminary alloy powder thus obtained was screened off to a size of <500 m and mixed with gas-atomized CuGa alloy powder (Ga content 25 at %), such that an Na content of Sat % was established.

(13) The CuGaNa powder mixture thus obtained was introduced into a tubular steel capsule, hot-degassed at 300 C. and sealed airtight. The powder was compacted by means of hot isostatic pressing at a temperature of 450 C., a pressure of 100 MPa.

(14) The blank thus obtained was subsequently processed by means of mechanical turning to give a tubular sputtering target of 155/135250 mm.

Example 3

(15) 5 kg of Ga were heated to 200 C. in an Ar protective gas atmosphere and melted in a graphite crucible by means of induction heating. Subsequently, 0.9 kg of Na was added (ratio in at % Ga/Na=65/35). In the course of this, the temperature was increased to 600 C. After the alloy had melted completely, atomization was effected by means of Ar gas to a spherical preliminary alloy powder.

(16) Subsequently, the preliminary alloy powder thus obtained was mixed with likewise gas-atomized CuGa alloy powder (Ga content 30 at %) to give a CuGaNa powder mixture having an Na content of 1 at %.

(17) The CuGaNa powder mixture thus obtained was compacted in a uniaxial hot press by means of spark plasma sintering (SPS) at a temperature of 400 C. to give a disc, and then processed to completion to give a disc-shaped sputtering target having a thickness of 5 mm and a diameter of 100 mm.

Example 4

(18) 1 kg of Ga was heated to 200 C. and melted in a graphite crucible by means of induction heating. Subsequently, 0.1 kg of Na was added (ratio in at % Ga/Na=75/25). The temperature was subsequently increased to 600 C. On completion of melting, the alloy was cast in a die made from hot-work steel.

(19) After solidification, the ingot thus produced was removed and, after complete cooling, comminuted with the aid of a jaw crusher and a cross-beater mill.

(20) Subsequently, the GaNa preliminary alloy powder thus obtained was screened off to <500 m and mixed with gas-atomized CuIn alloy powder (ratio in at % Cu/In=50/50) to give a powder mixture having an Na content of 5 at %.

(21) The CuGaInNa powder mixture thus obtained was subsequently compacted on a 3000 t press uniaxially at room temperature to give a disc-shaped blank. The blank thus obtained was subsequently processed to completion to give a sputtering target having a thickness of 5 mm and a diameter of 100 mm.

Example 5

(22) 5 kg of Ga were heated to 200 C. and melted in a graphite crucible by means of induction heating. Subsequently, 0.9 kg of Na was added (ratio in at % Ga/Na=65/35). In the course of this, the temperature was increased to 600 C. On completion of melting, the alloy was cast in a die made from hot-work steel.

(23) After solidification, the ingot thus produced was removed and, after complete cooling, comminuted with the aid of a jaw crusher and a cross-beater mill.

(24) Subsequently, the GaNa preliminary alloy powder thus obtained was screened off to a particle size of <500 m and mixed with gas-atomized CuGa alloy powder (Ga content 25 at %) to give a powder mixture having an Na content of 1 at %.

(25) The CuGaNa powder mixture thus obtained was introduced into a cylindrical steel capsule, hot-degassed at 300 C. and sealed air tight. The powder was compacted by means of hot isostatic pressing (HIP) at a temperature of 450 C. and a pressure of 100 MPa.

(26) The cylindrical blank thus obtained was subsequently separated from the steel can by means of mechanical turning and processed to a diameter of 60 mm and a length of 70 mm.

(27) The cylindrical blank was subsequently heated to 800 C. in a push-through furnace and extruded with a 100 t extrusion press to give a 1050 mm rectangular profile. This was used to manufacture a two-part target having a diameter of 100 mm.

Example 6

(28) 5 kg of In were heated to 300 C. and melted in a graphite crucible by means of induction heating. Subsequently, 0.8 kg of Na was added (ratio in at % In/Na=55/45). In the course of this, the temperature was increased to 500 C. On completion of melting, the alloy was cast in a die made from hot-work steel.

(29) After solidification, the ingot thus produced was removed and, after complete cooling, comminuted with the aid of a jaw crusher and a cross-beater mill.

(30) Subsequently, the InNa preliminary alloy powder thus obtained was screened off to a particle size of <500 m and mixed with gas-atomized CuIn alloy powder (In content 20 at %) to give a powder mixture having an Na content of 1 at %.

(31) The CuInNa powder mixture thus obtained was compacted to a disc in a uniaxial hot press at a temperature of 400 C., and then processed to completion to give a sputtering target having a thickness of 5 mm and a diameter of 100 mm.

Example 7

(32) 5 kg of In were heated to 300 C. and melted in an Ar protective gas atmosphere in a graphite crucible by means of induction heating. Subsequently, 1.15 kg of Na were added (ratio in at % In/Na=40/60). In the course of this, the temperature was increased to 500 C. On completion of melting of the alloy, atomization was effected by means of Ar gas to give a spherical preliminary alloy powder.

(33) Subsequently, the preliminary alloy powder thus obtained was mixed with likewise gas-atomized CuIn alloy powder (In content 30 at %) to give a CuInNa powder mixture having an Na content of 5 at %.

(34) The CuInNa powder mixture thus obtained was introduced into a tubular steel capsule, evacuated and sealed air tight. The powder was compacted by means of hot isostatic pressing at a temperature of 400 C. and a pressure of 100 MPa.

(35) The blank thus obtained was subsequently processed by means of mechanical turning to give a tubular sputtering target of 155/135250 mm.

Example 8

(36) 5.5 kg of Ga and 3.5 kg of In were heated to 250 C. and melted in a graphite crucible by means of induction heating. Subsequently, 0.1 kg of Na was added (ratio in at % Ga/In/Na=50/20/30). In the course of this, the temperature was increased to 550 C. On completion of melting, the alloy was cast in a die made from hot-work steel.

(37) After solidification, the ingot thus produced was removed and, after complete cooling, comminuted with the aid of a jaw crusher and a cross-beater mill.

(38) Subsequently, the GaInNa preliminary alloy powder thus obtained was screened off to a particle size of <500 m and mixed with gas-atomized CuInGa alloy powder (Ga content 10 at %, In content 40 at %) to give a powder mixture having an Na content of 5 at %.

(39) The CuGaInNa powder mixture thus obtained was compacted to a disc in a uniaxial hot press by means of spark plasma sintering (SPS) at a temperature of 400 C., and then processed to completion to give a disc-shape sputtering target having a thickness of 5 mm and a diameter of 100 mm.

Example 9

(40) 5.5 kg of Ga and 3.5 kg of In were heated to 250 C. and melted in a graphite crucible by means of induction heating. Subsequently, 0.1 kg of Na was added (ratio in at % Ga/In/Na=50/20/30). In the course of this, the temperature was increased to 550 C. On completion of melting, the alloy was cast in a die made from hot-work steel.

(41) After solidification, the ingot thus produced was removed and, after complete cooling, comminuted with the aid of a jaw crusher and a cross-beater mill.

(42) Subsequently, the GaInNa preliminary alloy powder thus obtained was screened off to a particle size of <500 m and mixed with gas-atomized CuIn alloy powder (In content 50 at %) to give a powder mixture having an Na content of 5 at %.

(43) The CuGaInNa powder mixture thus obtained was introduced into a tubular steel capsule, evacuated and sealed air tight. The powder was compacted by means of hot isostatic pressing at a temperature of 450 C. and a pressure of 100 MPa.

(44) The blank thus obtained was subsequently processed by means of mechanical turning to give a tubular sputtering target of 155/135250 mm.