共查询到18条相似文献,搜索用时 931 毫秒
1.
采用传输线模型测量了重B掺杂p型金刚石薄膜(约1020cm-3)上Ti/A u欧姆接触电阻率ρc,测试了500℃退火前后及大电流情况下的I-V特性,研究 了退火对ρc的影响.结果表明,重掺杂和退火工艺是改善欧姆接触的有效手段. ρc随测试温度的变化表明金属/半导体接触界面载流子输运机制为隧道穿透.而 光照对ρc影响的分析表明金刚石可作为理想窗口材料.测试得到的最低ρ c值约为10-4Ωcm2.
关键词:
金刚石薄膜
欧姆接触
接触电阻率 相似文献
2.
3.
4.
研究了Gd1-xCaxBa2Cu3O7-y(0.0≤X≤0.20)高温超导体在常压和高压下的超导电性在1-300K温度范围内,利用Bridgman对顶砧获得压力达9.0GPa,测量了(X=0.10,0.15,0.20)样品的dTc/dp分别为7.68,7.8和4.46K/GPa。发现Tc的压力导数随着ca2+含量的增加而下降,分析了氧含量对Tc和dTc/dP的影响.利用常压下晶格参数精修值和阳离子与氧离子间距随压力的改变,说明CuO2面在超导电性上的作用,用CuO2面之间耦合解释Tc(P)曲线的非线性关系。
关键词: 相似文献
5.
6.
本文提出一种测量金属-半导体体样品的接触电阻率ρc的方法——四点结构模型。四个金属电极的排列不受任何限制,导出了ρc的表达式。如果样品不是半无限大,而是有一定厚度的薄片,则必须进行修正,给出了修正因子。根据这个模型,进行实验测量和计算,所得结果与文献报道的一致。
关键词: 相似文献
7.
8.
对准二维电荷密度波导体磷酸钨青铜(PO2)4(WO3)2m(m=6)在2—300K温区内的磁电阻及在2K时的Δρ/ρ0-B关系进行了 实验研究.利用电子磁击穿模型对其低温端的磁阻增强行为进行了分析解释,理论和实验相 符合,并估算出高温端第一个Peierls能隙的大小为3.0meV,电子在低温下的迁移率为0.0 42m2V-1s-1
关键词:
低维导体磁电阻
电荷密度波 相似文献
9.
10.
应用传输线理论研究了金属薄膜Salisbury屏的反射率频谱特性,得到了Salisbury屏的反射系数公式和带宽系数的表达式.理论和数值分析表明,Salisbury屏的反射频谱是谐振型的;在谐振频率处,反射率的大小仅与金属薄膜的归一化面电阻α有关,而在其他频率处则取决于α和隔离层波阻抗η2.反射率带宽系数Δ取决于反射率的考察值Γα,η2和α.当α→αc,η2→η0时,Δ取得极
关键词:
Salisbury屏
反射率
频带宽度
金属薄膜 相似文献
11.
The Ti--Al ohmic contact to n-type 6H-SiC has been fabricated. An array of TLM
(transfer length method) test patterns with Au/Ti/Al/Ti/SiC structure is formed on
N-wells created by P+ ion implantation into Si-faced p-type 6H-SiC epilayer.
The specific contact resistance \rho c as low as 8.64×10-6\Omega\cdot cm2 is achieved after annealing in N2 at
900℃ for 5\,min. The sheet resistance Rsh of the implanted layers
is 975\Omega/\sqcap\!\!\!\!\sqcup. X-ray diffraction (XRD) analysis shows the
formation of Ti-3SiC2 at the metal/n-SiC interface after thermal annealing,
which is responsible for the low resistance contact. 相似文献
12.
In this study, the influence of the surface layer (p-InGaN or p-GaN) capping p-InGaN/p-GaN superlattices (SLs) on the contact to p-type GaN was investigated. It was found that the specific contact resistance (ρc) to p-type GaN is lower when using p-InGaN as the surface layer. The lowest value of ρc was 1.99×10−4 Ω cm2 at room temperature. It was also found that low temperature growth of the p-GaN layers in the SLs is beneficial for lowering the ohmic contact resistance. Unlike Ni/Au deposited directly on p-GaN (without the strained p-InGaN/p-GaN SLs), Ni/Au deposited on p-InGaN/p-GaN SLs produces ohmic behavior even before annealing. 相似文献
13.
Formation of the intermediate semiconductor larger for the Ohmic contact to silicon carbide using Germanium implantation 下载免费PDF全文
By formation of an intermediate semiconductor layer (ISL) with a
narrow band gap at the metallic contact/SiC interface, this paper
realises a new method to fabricate the low-resistance Ohmic contacts
for SiC. An array of transfer length method (TLM) test patterns is
formed on N-wells created by P+ ion implantation into
Si-faced p-type 4H-SiC epilayer. The ISL of nickel-metal Ohmic
contacts to n-type 4H-SiC could be formed by using Germanium ion
implantation into SiC. The specific contact resistance ρc as low as 4.23× 10-5~Ωega \cdotcm2 is
achieved after annealing in N2 at 800~°C for 3~min,
which is much lower than that (>900~°C) in the typical SiC
metallisation process. The sheet resistance Rsh of the
implanted layers is 1.5~kΩega /\Box. The technique for
converting photoresist into nanocrystalline graphite is used to
protect the SiC surface in the annealing after Ge+ ion
implantations. 相似文献
14.
The influence of electronic transport across interface junction between Si substrate and the root of ZnO micro-prism on field emission performance 下载免费PDF全文
ZnO micro-prisms are prepared on the p-type and n-type Si substrates,
separately. The $I$--$V$ curves analysed by AFM show that the interface junctions
between the ZnO micro-prisms and the p-type substrate and between the ZnO
micro-prisms and the n-type Si substrate exhibit p--n junction behaviour and
ohmic contact behaviour, respectively. The formation of the p--n
heterojunction and ohmic contact is ascribed to the intrinsic n-type
conduction of ZnO material. Better field emission performance (lower onset
voltage and larger emission current) is observed from an individual ZnO
micro-prism grown on the n-type Si substrate. It is suggested that the
n-Si/n-ZnO interfacial ohmic contact benefits the electron emission; while
the p-Si/n-ZnO interface heterojunction deteriorates the electron emission. 相似文献
15.
The structural and electronic properties of the intermixed interfaces of layered Au/Te/n-GaAs structures were investigated by the combined application of129I Mössbauer spectroscopy (in the decay of129mTe), X-ray diffraction, Raman spectroscopy and electrical measurements. The transition from Schottky-type to ohmic contact by high fluence pulsed laser irradiation was examined and compared to rapid time furnace heat treatment. Distinctly different ohmic contact formation mechanisms have been observed. Whereas for furnace alloying the formation of a crystalline (graded As doped) Ga2Te3 interface layer is crucial, strong evidence is adduced that the ohmic character of high-fluence laser mixed structures is correlated to the formation of a high density of defect complexes in the GaAs top layer. 相似文献
16.
H. Wang W. Winterbach P. Van Mieghem 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,83(2):203-214
Newman's measure for (dis)assortativity, the linear degree correlationρ D , is widely studied although analytic insight into the assortativity of an arbitrary network remains far from well understood. In this paper, we derive the general relation (2), (3) and Theorem 1 between the assortativity ρ D (G) of a graph G and the assortativityρ D (G c) of its complement G c. Both ρ D (G) and ρ D (G c) are linearly related by the degree distribution in G. When the graph G(N,p) possesses a binomial degree distribution as in the Erd?s-Rényi random graphs G p (N), its complementary graph G p c (N) = G 1- p (N) follows a binomial degree distribution as in the Erd?s-Rényi random graphs G 1- p (N). We prove that the maximum and minimum assortativity of a class of graphs with a binomial distribution are asymptotically antisymmetric: ρ max(N,p) = -ρ min(N,p) for N → ∞. The general relation (3) nicely leads to (a) the relation (10) and (16) between the assortativity range ρ max(G)–ρ min(G) of a graph with a given degree distribution and the range ρ max(G c)–ρ min(G c) of its complementary graph and (b) new bounds (6) and (15) of the assortativity. These results together with our numerical experiments in over 30 real-world complex networks illustrate that the assortativity range ρ max–ρ min is generally large in sparse networks, which underlines the importance of assortativity as a network characterizer. 相似文献
17.
K. Sugioka K. Toyoda K. Tachi M. Otsuka 《Applied Physics A: Materials Science & Processing》1989,49(6):723-727
Carbon doping of GaAs using a KrF excimer laser to form a p-type active layer is described. Methane gas (CH4) was used as a source of the C acceptor. Various quantities such as sheet resistance, surface carrier density, Hall mobility, and depth profile of C-doped GaAs are measured as the functions of laser fluence and laser pulse. It is shown that C atoms are doped only within a limited depth as shallow as 50 nm or less and with extremely high concentration exceeding 1×1021 cm–3. The maximum activation efficiency is found to be 69.0%. Laser induced changes of surface morphologies and electron diffraction patterns are also discussed. Furthermore, non-alloyed ohmic contacts using laser-doped p-type GaAs are demonstrated. 相似文献
18.
本文用AES和SIMS分析讨论了p-GaP与三层金属膜Pd/Zn/Pd形成良好欧姆接触层的性质. 相似文献