Si,S,Be,Mg离子注入GaAs白光快速退火特性研究

利用灯光瞬态退火处理Si,S离子注入SI-GaAs样品,在950℃5秒的条件下得到了最佳的电特性,Be,Mg离子注入SI-GaAs样品在800℃ 5秒退火得到了最佳的电特性.Si,S,Be注入GaAs样品在适当的条件下得到了陡峭的载流子剖面分布,而Mg注入的样品有Mg的外扩散和较大的尾部扩散.透射电镜测量表明,Si低剂量和Be大剂量注入退火后单晶恢复良好,而Si和Mg大剂量注入退火后产生了大量的二次缺陷.应用Si和Mg注入GaAs分别制作了性能良好的MESFET和β=1000的GaAIAs/GaA,双极型晶体管(HBT).     

离子注入及退火对GaAs/Si晶体完整性影响的研究

本文用4.2MeV ~7Li离子卢瑟福背散射沟道技术研究了Si上外延GaAs膜在MeV Si离子注入及红外瞬态退火后的再生长过程。实验表明,离子注入可使GaAs外延膜内形成一无序网络,当注入剂量低于某一阈值时,850℃,15秒退火后,损伤区可完全再结晶,再结晶后的GaAs层的晶体质量特别在界面区有很大的改善;当剂量超过该阈值时,出现部分再结晶。激光Raman实验也表明,经过处理后的GaAs层Raman谱TO/LO声子的比率比原生长的样品有很大的降低。     

Si^＋,As^＋双离子注放半绝缘GaAs的无包封快速热退火技术的研究

本文采用清华大学ＱＳＷ－３０７５快速热处理设备对Ｓｉ＾＋，Ａｓ＾＋双离子注入半绝缘ＧａＡｓ进行了快速热退火研究。结果表明，在适当条件下退火，注入杂质有高的激活效率，并且杂几乎没有因高温退火引起的扩散再分布，保留了原有的注入分布。在加热位置降温可消除注入晶片滑移的产生。     

半导体材料Si与GaAs的发展前景

随着微电子技术向高密集度、高可靠性方向发展,对半导体材料的要求也越来越高。GaAs材料的异军突起,打破了Si材料一统天下的局面。通过对它们的材料特性和器件特性进行比较,我们发现:只有兼二者之长的材料才能满足未来器件的需要。     

用于GaAs贯穿注入和包封退火的AIN薄膜

用直流反应溅射淀积的AIN薄膜作包封介质对GaAs进行了贯穿注入和包封退火。用电化学C－V法测量了载流子的分布。实验结果与TRIM模拟结果符合得很好。用50nm的AIN包封进行贯穿注入和退火，得到了较小的标准偏差，较陡峭的载流子分布和较高的激活率。应用AIN包封层后，当注入能量180keV，注入剂量7．5×10~13cm~－2时，所得到的最高载流子浓度为1．84×10~18cm~－3，样品方块电阻为118Ω／□。     

As注入长波碲镉汞红外探测器工艺研究

p-on-n结构的碲镉汞红外探测器具有长的少子寿命、低暗电流、高R0A值等优点,是高温器件、长波甚长波器件发展的重要器件结构.而国内还鲜有砷注入掺杂p-on-n长波HgCdTe探测器的相关报道,为了满足军事、航天等领域对高性能长波探测器迫切的应用需求,针对As离子注入的长波p-on-n碲镉汞红外探测器退火工艺技术进行研...     

DEEP LEVEL DEFECTS IN SI-IMPLANTED LEC UNDOPED Si-GaAs

The residual electrically active defects in(4×10~(12)cm~(-2)(30KeV)+5×10~(12)cm~(-2)(130KeV))si-implanted LEC undoped si-GaAs activated by two-step rapid thermal annealing(RTA)LABELED AS 970℃(9S)+750℃(12S)have been investigated with deep level transient spec-troscopy(DLTS).Two electron traps ET_1(E_c-0.53eV,σ_n=2.3×10~(-16)cm~2)and ET_2(E_c-0.81eV,σ_n=9.7×10(-13)cm~2)are detected.Furthermore,the noticeable variations of trap's con-centration and energy level in the forbidden gap with the depth profile of defects induced by ion im-plantation and RTA process have also been observed.The[As_i·V_(As)·As_(Ga)]and[V_(As)·As_i·V_(Ga)·As_(Ga)]are proposed to be the possible atomic configurations of ET_1 and ET_2,respectively to explaintheir RTA behaviors.     

Si-implantation into GaAs grown on Si

200 keV Si implantations were performed in the dose range of 5 × 10¹² − 1 × 10¹⁴ cm⁻² in GaAs grown on Si. For comparison implants were also performed in GaAs layers grown on GaAs substrates. Implanted layers were annealed by both furnace and halogen lamp rapid thermal anneals. Significantly lower donor activations were observed in GaAs layers grown on Si substrates than in the layers grown on GaAs substrates. Extremely low dopant activations were obtained for Be implants in GaAs grown on Si. Photoluminescence and photoreflectance measurements were also performed on the implanted material.     

热处理中As压对半绝缘GaAs缺陷的影响

在 95 0°C和 1 1 2 0°C温度下 ,对非掺杂半绝缘 LECGa As进行了不同 As气压条件下的热处理 ,热处理的时间为 2～ 1 4小时。发现不同 As压条件下的热处理可以改变 Ga As晶片的化学配比 ,并导致本征缺陷和电参数的相应变化。在 95 0°C和低 As气压条件下进行 1 4小时热处理 ,可在样品体内 (表面 1 5 0 μm以下 )引入一种本征受主缺陷 ,使电阻率较热处理前增加约 5 0 % ,霍尔迁移率下降 70 %。这种本征受主缺陷的产生是由于热处理过程中样品内发生了 As间隙原子的外扩散。提高热处理过程中的 As气压可以抑制这种本征受主缺陷的产生。真空条件下在 1 1 2 0°C热处理 2～ 8小时并快速冷却后 ,样品中的主要施主缺陷 EL2浓度约下降一个数量级 ,提高热处理过程中的 As气压可以抑制 EL2浓度下降。这种抑制作用是由于在高温、高 As气压条件下 ,发生了间隙原子向样品内部的扩散     

Application of low temperature GaAs to GaAs/Si

Low Temperature grown GaAs (LT-GaAs) was incorporated as a buffer layer for GaAs on Si (GaAs/Si) and striking advantages of this structure were confirmed. The LT-GaAs layer showed high resistivity of 1.7 × 10⁷ ω-cm even on a highly defective GaAs/Si. GaAs/Si with the LT-GaAs buffer layers had smoother surfaces and showed much higher photoluminescence intensities than those without LT-GaAs. Schottky diodes fabricated on GaAs/Si with LT-GaAs showed a drastically reduced leakage current and an improved ideality factor. These results indicate that the LT-GaAs buffer layer is promising for future integrated circuits which utilize GaAs/Si substrates.     

MOCVD GaAs/Si兼容技术及其应用

本文着重论述用MOCVD方法生长GaAs/Si的工艺技术及存在的问题。     

Properties of a poly-Si/GaAs layered structure on Si for Si heterojunction bipolar transistor

The properties of poly-Si/GaAs layered films on Si for use in wide bandgap emitters for Si heterojunction bipolar transistors (Si-HBTs), were studied. A smooth GaAs film surface grown on Si was obtained at low temperature (200° C) from the initial stage of growth. The x-ray diffraction (XRD) results indicated that strong GaAs orientation (111) was obtained for the poly-Si/GaAs/Si-substrate layered structure after annealing at 800° C for 20 sec. Secondary ion mass spectroscopy (SIMS) profiles indicated that impurity diffusion from the GaAs layer into the p-type Si substrate was negligible at 800° C. The electrical characteristics forn-poly-Si/n-GaAs/p-Si-substrate heterojunction diodes were also investigated.     

非掺SI-GaAs单晶热处理的研究

采用闭管Ａｓ气氛保护高－低－中温热处理方法进行非掺ＳＩ－ＧａＡｓ单晶热处理的研究，结果表明晶体的特性有明显的改善，一般晶体的迁移率可提高一倍以上，在Φ３英寸非掺ＳＩ－ＧａＡｓ单晶研究中，其晶体的电阻率不均匀性≤１５％；ＥＬ２ＲＳＤ≤５％；ＰＬ－Ｍａｐ－ｐｉｎｇ≤９％。     

Characteristics of Si3N4/GaAs metal-lnsulator-semiconductor interfaces with coherent Si/Al0.3Ga0.7As interlayers

Si₃N₄/GaAs metal-insulator-semiconductor (MIS) interfaces with Si(10Å)/ Al_0.3Ga_0.7As (20Å) interface control layers have been characterized using capacitance-voltage (C-V) and conductance methods. The structure was in situ grown by a combination of molecular beam epitaxy and chemical vapor deposition. A density of interface states in the 1.1 × 10¹¹ eV^-1 cm^-2 range near the GaAs midgap as determined by the conductance loss has been attained with an ex situ solid phase annealing of 600°C in N₂ ambient. A dip quasi-static C-V demonstrating the inversion of the minority-carrier verifies the decent interface quality of GaAs MIS interface. The hysteresis and frequency dispersion of the MIS capacitors were lower than 100 mV, some of them as low as 50 mV under a field swing of about ±2 MV/cm. The increase of the conductance loss at higher frequencies was observed when employing the surface potential toward conduction band edge, suggesting the dominance of faster traps. Self-aligned gate depletion mode GaAs metal-insulator-semiconductor field-effect transistors with Si/Al_0.3Ga_0.7As interlayers having 3 μm gate lengths exhibited a transconductance of about 114 mS/mm. The present article reports the first application of pseudomorphic Si/ Al_0.3Ga_0.7As interlayers to ideal GaAs MIS devices and demonstrates a favorable interface stability.     

(Ga,Mn,As)/GaAs的发光谱

利用低能双离子束外延技术 ,在 4 0 0℃条件下生长样品 (Ga,Mn,As) / Ga As.样品光致发光谱出现三个峰 ,即1.5 0 4 2 e V处的 Ga As激子峰、1.4 875 e V处的弱碳峰和低能侧的一宽发光带 .宽发光带的中心位置在 1.35 e V附近 ,半宽约 0 .1e V.在 84 0℃条件下对样品进行退火处理 ,退火后的谱结构类似退火前 ,但激子峰和碳杂质峰的峰位分别移至 1.5 0 6 5 e V和 1.4 894 e V,同时低能侧的宽发光带的强度大大增加 .这一宽发射带的来源还不清楚 ,原因可能是体内杂质和缺陷形成杂质带 ,生成 Mn2 As新相 ,Mn占 Ga位或形成 Ga Mn As合金     

Hydrogen plasma passivation of bulk GaAs and Al0.3Ga0.7As/GaAs multiple-quantum-well structures on Si substrates

Hydrogen (H) plasma passivation effects on GaAs grown on Si substrates (GaAs on Si) are investigated in detail. H plasma exposure effectively passivates both the shallow and deep defects in GaAs on Si, which improves both the electrical and optical properties. It was found that the minority carrier lifetime is increased and the deep level concentration is decreased by the H plasma exposure. In addition, after H plasma exposure, room temperature photoluminescence (PL) for Al_0.3Ga_0.7As/GaAs multiple-quantum-well (MQW) on Si is enhanced with a decrease in the spectral width.