Si衬底GaN基LED外延薄膜转移至金属基板的应力变化

采用电镀金属基板及湿法腐蚀衬底的方法将硅衬底上外延生长的GaNMQWLED薄膜转移至不同结构的金属基板,通过高分辨X射线衍射(HRXRD)和光致发光(PL)研究了转移的GaN薄膜应力变化。研究发现:(1)转移至铜基板、铬基板、铜/镍/铜叠层基板等三种基板的GaN薄膜张应力均减小,其中转移至铬基板的GaN薄膜张应力最小。(2)随着铬基板中铬主体层厚度的增加,转移后的GaN薄膜应力不发生明显变化。

Investigation of Strain of GaN Light-emitting Diode Films Transferred to Metal Substrate from Si(111)

GaN-based MQW light-emitting diode films was transferred to metal substrate from Si(111) substrate by electro-plating and chemical etching. Then, high resolution X-ray diffraction(HRXRD) and photoluminescence(PL) was used to investigate the strain of GaN films in the transfer process. In the study, we designed a series of metal substrates of different structure: (1) Copper substrate, (2)chrome substrate and (3)copper/nickel/copper substrate because of their special thermal and mechanical properties. It was revealed that the tensile strain of GaN films decreases when it is transferred from Si(111) substrate to such three kinds of metal substrates, which is propitious to GaN films. And there is a maximal decrease of tensile strain when GaN films are transferred to chrome substrate. The main layer of electro-plating chrome in the chrome substrate is playing an important role in the sustentation to GaN films. And it was found that, with the thickness increasing of main layer, the strain of GaN films has no change, so the thickness of main layer could be added as more as possible, which can enhance the mechanical properties of chips in the manufacture process.