Reducing GaN-on-diamond interfacial thermal resistance for high power transistor applications
Reducing GaN-on-diamond interfacial thermal resistance for high power transistor applications
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DOI：
10.1063/1.4913430
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发表时间：
2015-03-16
影响因子：
4
通讯作者：
Kuball, Martin
中科院分区：
文献类型：
--
作者：
Sun, Huarui;Simon, Roland B.;Kuball, Martin
化学气相沉积多晶金刚石的集成为GaN基高功率射频放大器提供了有前途的热性能。一个限制因素是GaN与金刚石界面处的热障，通常称为有效热边界电阻（TBReff）。使用瞬态热反射测量，有限元建模和微观结构分析的组合，GaN上的金刚石晶片的TBReff被示出为占主导地位的SiNx夹层金刚石生长播种，从金刚石成核表面的额外影响。通过减小SiNx层厚度和最小化金刚石成核区域，可以显著降低TBReff，并且证明TBReff低至12 m（2）K/GW。这使得相对于SiC上GaN晶片，金刚石上GaN晶体管的热阻能够得到重大改善。还预测了TBReff朝向扩散失配极限的进一步减少，证明了使用金刚石作为散热衬底的全部潜力。(C)2015 AIP Publishing LLC.
Integration of chemical vapor deposited polycrystalline diamond offers promising thermal performance for GaN-based high power radio frequency amplifiers. One limiting factor is the thermal barrier at the GaN to diamond interface, often referred to as the effective thermal boundary resistance (TBReff). Using a combination of transient thermoreflectance measurement, finite element modeling and microstructural analysis, the TBReff of GaN-on-diamond wafers is shown to be dominated by the SiNx interlayer for diamond growth seeding, with additional impacts from the diamond nucleation surface. By decreasing the SiNx layer thickness and minimizing the diamond nucleation region, TBReff can be significantly reduced, and a TBReff as low as 12 m(2)K/GW is demonstrated. This enables a major improvement in GaN-on-diamond transistor thermal resistance with respect to GaN-on-SiC wafers. A further reduction in TBReff towards the diffuse mismatch limit is also predicted, demonstrating the full potential of using diamond as the heat spreading substrate. (C) 2015 AIP Publishing LLC.