排序方式: 共有5条查询结果,搜索用时 15 毫秒
1
1.
In this paper we propose a new method for measuring the thickness of the GaN epilayer, by using the ratio of the integrated intensity of the GaN epilayer X-ray diffraction peaks to that of the sapphire substrate ones. This ratio shows a linear dependence on the GaN epilayer thickness up to 2 μm. The new method is more accurate and convenient than those of using the relationship between the integrated intensity of GaN epilayer diffraction peaks and the GaN thickness. Besides, it can eliminate the absorption effect of the GaN epilayer. 相似文献
2.
3.
采用双晶X射线衍射(DC-XRD)研究蓝宝石(0001)衬底上横向外延GaN层中晶面倾斜的形成原因. 发现横向生长区的GaN在垂直掩模方向上朝SiNx掩模层弯曲. 采用选择性腐蚀逐渐去掉SiNx掩模层, 发现XRD中GaN(0002)w扫描衍射峰两侧存在与晶面倾斜有关的衍射信息. 该衍射信息起初为一个很宽的峰, 随着选择性腐蚀的进行, 会先分裂为两个峰, 最后当SiNx掩模层全部腐蚀掉后, 其中一个衍射峰会消失, 而只剩下一个很窄的峰. 作者证实造成横向外延GaN 中晶面倾斜的原因有两个: 一是由于GaN与掩模层之间界面应力造成的弹性非均匀应变; 另一个是由于GaN中穿透位错的90°转向造成的塑性形变. 相似文献
4.
Metal-semiconductor-metal ultraviolet photodetector based on GaN 总被引:1,自引:0,他引:1
A metal-semiconductor-metal (MSM) ultraviolet photodetector has been fabricated using unintentionally doped n-GaN films grown on sapphire substrates. Its dark current, photocurrent under the illumination with λ = 360 nm light, responsivity, and the dependence of responsivity on bias voltage were measured at room temperature. The dark current of the photodetector is 1.03 Na under 5 V bias, and is 15.3 Na under 10 V bias. A maximum responsivity of 0.166 A/W has been achieved under the illumination with λ= 366 nm light and 15 V bias. It exhibits a typical sharp band-edge cutoff at the wavelength of 366 nm, and a high responsivity at the wavelength from 320 nm to 366 nm. Its responsivity under the illumination with λ= 360 nm light increases when the bias voltage increases. 相似文献
5.
The crystallographic tilt in GaN layers grown by epitaxial lateral overgrowth (ELO) on sapphire (0001) substrates was investigated
by using double crystal X-ray diffraction (DC-XRD). It was found that ELO GaN stripes bent towards the SiNx mask in the direction perpendicular to seeding lines. Each side of GaN (0002) peak in DC-XRD rocking curves was a broad peak
related with the crystallographic tilt. This broad peak split into two peaks (denoted as A and B), and peak B disappeared
gradually when the mask began to be removed by selective etching. Only narrow peak A remained when the SiNx mask was removed completely. A model based on these results has been developed to show that there are two factors responsible
for the crystallographic tilt: One is the non-uniformity elastic deformation caused by the interphase force between the ELO
GaN layer and the SiNx mask. The other is the plastic deformation, which is attributed to the change of the threading dislocations (TDs)—from vertical
in the window regions to the lateral in the regions over the mask. 相似文献
1