www morganproject eu Materials for Robust Gallium Nitride

www. morganproject. eu Materials for Robust Gallium Nitride Michał A. Borysiewicz, Eliana Kamińska, Anna Piotrowska Institute of Electron Technology Warsaw, Poland E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw

www. morganproject. eu Outline • • Introduction to the MORGa. N project Overview of each topic + results Training opportunities Contact information E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 2

www. morganproject. eu Introduction E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 3

www. morganproject. eu MORGa. N- Materials for Robust Gallium Nitride Robust – capable of performing without failure under a wide range of conditions Merriam-Webster Dictionary Ga. N – wide band-gap semiconductor E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 4

www. morganproject. eu Why Ga. N? • Advantages over traditional semiconductors – Thermal & chemical stability (operation > 1000ºC) – High breakdown fields (DC to microwave > 5 MVcm-1) • Potential for technology improvements – Power electronics – Harsh environment sensors • Drawbacks – Limited wafer availability – Material quality problems • Defects & intrinsic material strain E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 5

www. morganproject. eu Key objectives of the Project Develop Ga. N sensors & microwave transistors for harsh environments • Materials – New nitride growth techniques – Novel diamond composite substrates – Diamond passivation • Processing • Packaging E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 6

www. morganproject. eu MORGa. N topics 1. ) III-V materials • Improved Ga. N films – Low stress and low defect density – Optimisation of In. Al. N/Ga. N heterostructures 2. ) Diamond-based materials • Innovative diamond-based composite substrates • Nanocrystalline diamond coatings for passivation & heat removal 3. ) Harsh environment devices • High power electronic devices • Sensors for harsh environments 4. ) Packaging and metallisation • For harsh environment applications. E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 7

www. morganproject. eu MORGa. N consortium UK GERMANY SWEDEN POLAND CZECH REPUBLIC SLOVAKIA FRANCE HUNGARY AUSTRIA SWITZERLAND 24 partners; 11 nations Project lead organisation: Alcatel-Thales III-V Labs E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw GREECE 8

www. morganproject. eu Topics & results E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 9

www. morganproject. eu 1. ) III-V materials Objectives – New substrates for low defect density Ga. N • Polycrystalline diamond/Si sandwich hybrid substrates • Compliant heterostructures for growing Ga. N film – Growth optimisation of In. Al. N/Ga. N heterostructures • Harsh environment electronic & sensing applications Novel approaches – New Inx. Al 1 -x. N/Ga. N heterostructures • Lower intrinsic mechanical stress • Minimises material degradation • Originally developed in FP 6 www. ultragan. eu – “Nano-columns" technique • Developed at the University of Bath • Used to grow low defect density Ga. N film. E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 10

www. morganproject. eu MORGa. N technology 1 Nano-columns Seeded nano-columns a) Arbitrary substrate Seed layer b) Near defect-free epi-layer (formed by coalescence of nano-columns) c) Nano-columns distort to accommodate strain and deflect dislocations E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 11

www. morganproject. eu 2. ) Diamond-based materials Diamond – Highest thermal conductivity of any solid ~2000 Wm-1 K-1 in high quality CVD diamond – Potentially the ultimate substrate for high temperature & extreme power applications Ga. N alloys – Impressive power handling capability Objectives MORGa. N will develop diamond/ Ga. N hybrids – Thermal behaviour of diamond. – Electrical efficiency of Ga. N E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 12

www. morganproject. eu MORGa. N technology 2 Nano-crystalline diamond coating • Diamond overgrowth for thermal management • Large area diamond overgrowth – Polycrystalline diamond deposition by hot-filament CVD Typical HEMT Simulation of performance structure of HEMTs/ Al 2 O 3 and Si. C Sapphire Sub. Si. C Sub. Diamond (Sapphire Sub. ) Diamond (Si. C Sub. ) E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 13

www. morganproject. eu 3. ) Harsh environment devices “External harsh environment” • • Extreme heat Pressure High electric fields Chemically aggressive substances. “Internal harsh environment” • Power dissipation from large current flow at high bias E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 14

www. morganproject. eu 3. ) Harsh environment devices • Cantilever pressure sensor • Drumskin pressure sensor • 1 k. W 2 GHz power bar E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 15

www. morganproject. eu MORGa. N technology 3 Cantilever pressure sensor • Based on a double cantilever design chip ‒ One cantilever deflected by a probe attached to a flexible membrane ‒ Second cantilever – reference for temperature compensation • Signal – due to the piezo-electric effect in the Ga. N under strain Sensor chip Solder pads optical microscope image of a Ga. N-based cantilever deflection measured using optical interferometry E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw Temperature sensor Double cantilever structure 16

www. morganproject. eu MORGa. N technology 3 Drumskin pressure sensor Alternative design: HEMT sensor directly integrated in a diaphragm • Diaphragm used for the detection of pressure (100 – 1000 atm) • Membrane strain transferred to a Ga. N-based sensing device • Circular HEMT as a pressure sensing device Advantages to this design: • Simple C-HEMT fabrication and integration on membrane structure • Parasitic gate leakage current significantly suppressed • A large gate area easily achieved. E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 17

www. morganproject. eu MORGa. N technology 3 Towards a 1 k. W 2 GHz power bar demonstrator 250 W power chip specified and designed • 90 fingers (each 400µm long) • Die size 1 mm x 5 mm • Four chips be co-packaged to build a 1 k. W device Test chips manufactured and tested • 2 mm power cells • DC and CW characterisation performed • Very good yield obtained on power device and power die • State-of-the-art results! 6. 6 W/mm and 70% PAE @3. 5 GHz E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 18

www. morganproject. eu 4. ) Packaging and metallisation Objectives To develop packaging and metallisation solutions that are: – Thermally stable and compatible – Chemically stable MORGa. N novel approaches – Advanced 3 D ceramic packaging – New metallisation techniques • Emerging technology of MN+1 ANX alloys – Ceramic/ metal systems for high temperature applications – Novel layer package manufacture techniques • Permit very complex geometrical package and interconnect structures E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 19

www. morganproject. eu MORGa. N technology 4 Layer manufacturing Novel process to produce steel parts using ink-jet technology – Process uses a fine stainless steel powder (316 L) – Sintered to full density – Other steels & metals (e. g. Ti) also possible – Resolution c. 20 m (x, y); 40 m (z) – Surface finish c. 4 m Large geometric freedom – Complex shapes for novel packaging possible. Dual purpose housings for either cantilever chip or drumskin device E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 20

www. morganproject. eu Training opportunities E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 21

www. morganproject. eu MORGa. N training opportunities • MORGa. N offers many training opportunities – Ph. D. students • Advanced and emerging knowledge on thesis topics • Wider technological context – Established researchers and technologists • Wide scope for new skills & information • Residential course, May’ 10, Bratislava – Advanced instruction on core MORGa. N topics • Workshop – To be held in the second half of the project • Research visits between MORGa. N partners – Extended research visits (1 -12 weeks duration) – Postgraduate student/ experienced researcher level. E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 22

www. morganproject. eu Contact information E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 23

www. morganproject. eu MORGa. N contact information For more information: – Project leader • Sylvain Delage; Alcatel-Thales III-V Lab sylvain. delage@3 -5 lab. fr – Dissemination • Bruce Napier; Vivid Components bruce@vividcomponents. co. uk – Website : www. morganproject. eu Sign up for newsletter! E-MRS Fall ‘ 10, 16 Sept. 2010, Warsaw 24