【作者】 熊贻婧；

【导师】 张萌； 熊传兵；

【作者基本信息】 南昌大学 ， 材料物理与化学， 2010， 硕士

【摘要】 电镀金属基板的最显著优势是提高GaN LED的散热性能和光电特性,尤其是大功率GaN LED。目前,将蓝宝石、SiC衬底GaN薄膜转移至电镀基板的技术已经得到了广泛的研究。然而据我们所知,有关Si衬底GaN薄膜转移至电镀基板研究的报道很少,而对转移前后应力变化的研究还未曾有过报道。本文采用电镀金属基板和化学腐蚀的方法将Si衬底GaN LED薄膜转移至金属基板,并结合高分辨X射线衍射(HRXRD)和光致发光(PL)的方法研究转移对GaN薄膜应力的影响。此外,为了改善电镀基板结构,本文初步摸索了图形化电镀方法。本文的主要研究内容和结果如下：1.本文制备了铜基板、铬基板、铜／镍／铜叠层基板等三种电镀基板,然后采用HRXRD和PL研究转移至这些电镀基板的GaN薄膜应力状况。应力分析表明：GaN薄膜从Si衬底转移至这三种电镀基板后,由外延生长引入的张应力都得到了释放,其中铬基板GaN薄膜的张应力最小。2.本文中的铬基板是由铜过渡层和铬主体层组成的。通过对铬主体层的厚度进行改变发现：随着电镀的铬基板中铬主体层厚度的增加,转移至铬基板的GaN薄膜应力不发生明显变化。3.本文采用光刻胶涂覆晶片沟槽,使电镀过程中金属材料被分开沉积。通过这种方法制作的铜基板呈现出了清晰明显的图形化,厚度约为20μm。后来通过采用两次该方法使图形化铜基板厚度达到了约40μm,然而第二次的铜层呈现出了粗糙的边缘。4.本文验证了铬不能直接电沉积在铂上,因此将铂沉积在沟槽里,以防止铬在沟槽上方形成。然而,通过这种方法制作的铬基板没能呈现出图形化,因为在电镀之前一些铂从沟槽里脱落下来,而剩下的铂在电镀过程中被铬覆盖,这些铬是从侧边生长过来的,而不是在铂上直接电沉积的。更多还原

【Abstract】 Plating metal substrate has the most prominent advantages of enhancing the thermal conductivity, optical and electrical properties of GaN LED, especially the high-power GaN LED. At present, there has been an extensive investigation on the GaN films transfer from sapphire or SiC substrate to plating substrate. Whereas, there has been a few reports about the transfer of silicon substrate GaN films, and by now even no research on the stress transformation in the film transfer, according to our knowledge。In this thesis, plating and chemical etching method was adopted to transfer GaN films from silicon to metal substrate, and the stress transformation caused by transfer was researched by HRXRD (high resolution X-ray diffraction) and PL (photoluminescence)method. In addition, for the improvement of substrate structure, pattern plating method was investigated. To sum up, the main content of this thesis and some main conclusions are as follows:1. Three kinds of plating substrates were prepared, including copper, chrome and copper/nickel/copper substrates. Then HRXRD and PL were used to investigate the stress of GaN films on those plating substrates. And the stress analysis showed that, the tensile stress in GaN films caused by epitaxial growth can be released when GaN films was transferred to those plating substrates from silicon substrate. And the GaN films on chrome substrate had a least tensile stress.2. In this thesis, the chrome substrate were composed of copper transition layer and chrome sustentation layer. Then the thickness of chrome sustentation layer was investigated. And it was recognized that the thickness of chrome sustentation layer had no obvious influence on the stress of GaN films on the chrome substrate.3. In this thesis, photoresist was used to cover the groove on the wafer, which can made metal meterial electrodeposite dividually in the plating process. And the copper substrate fabricated by this method showed a transparent pattern with thickness of about 20 micron. Afterward, the thickness of pattern copper substrate reached about 40 micron by using that method twice, however, the second copper layer presented a rough edge.4. In this thesis, it was recognized that chrome can not electrodeposite directly on platinum. So platinum was deposited on the groove, in order to prevent chrome form above the groove. However, the chrome substrate prepared by this method can not show any pattern, because some platinum fell off the groove before plating and the rest platinum can be coverd by chrome which growed from side, not directly electrodeposited on platinum.更多还原