半绝缘GaAs中Mg~++P~+双注入研究

本文对Mg~+和P~+双离子注入半绝缘GaAs的行为进行了研究.发现不论是常规热退火还是快速热退火,共P~+注入都能有效地提高注入Mg杂质的电激活率,其效果优于共As~+注入,共P~+注入的最佳条件是其剂量与Mg~+离子剂量相同,电化学C—V测量表明,双注入样品中空穴分布与理论计算值接近,而单注入样品中则发生严重偏离,快速热退火较常规热退火更有利于消除注入损伤.     

InP和GaAs中的Mg~+离子注入

本文研究了Mg~+离子注入InP和GaAs中的电学性能和辐射损伤行为.范德堡霍尔方法测量和电化学C-V测量均表明,快速热退火方法优于常规热退火方法,共P~+注入结合快速热退火方法能进一步减小注入Mg杂质的再分布,使电激活率大大提高。卢瑟福沟道分析则表明,相同注入条件下,InP中的辐射损伤较GaAs中大得多,大剂量注入损伤经热退火难于完全消除.     

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双注入GaAs的RTA研究

本文研究了Si注入GaAs的快速退火(RTA)特性。得出930—950℃退火5s为最佳退火条件。测量结果表明,当注入剂量大于10~(13)cm~(-2)时,电子浓度呈饱和现象。为提高电子浓度本文提出Si,As双注入GaAs的方法,研究了(60—80)keV,(5—10)×10~(14)Si/cm~2+(150—180)keV,(5—30)×10~(14)As/cm~2注入并经RTA后的电特性。结果表明,双注入后样品中电子浓度有明显提高,对80keV,10~(15)Si/cm~2+150keV,3×10~(15)As/cm~2来说,电子浓度大于10~(19)cm~(-3)。TEM观察表明,双注入样品的剩余缺陷密度大大低于单注入的情况。本文并对双注入补偿机理进行了讨论。     

高能Si~+注入Sl-GaAs形成n型埋层

本文报导0.6～5MeV高能Si~+离子注入LEC半绝缘GaAs的快速退火效果,在950℃温度下退火5秒得到最佳电特性.采用多能量叠加注入已制备出平均深度在1.2μm,厚约1.7μm的n~+深埋层,载流子浓度为3～5×10~(17)cm~(-3).在近表面单晶层上作成了性能良好的肖特基接触,其势垒高度约为0.7V.     

GaAsIC工艺中的快速热退火

目前在常规炉内完成的GaAs IC工艺过程的各种退火步骤可以很容易地转到方便的快速退火炉中进行。本文比较了注入到半绝缘GaAs中常用的离子(Si、Se、Be、Mg和Zn)经过两种退火方式所得到的激活特性,并讨论了在包封要求、产量和操作方面两种方法的局限性和优越性。     

GaAs快速退火:激活率的均匀性及其与温度的关系

在2in和3in的SI-GaAs衬底上进行Si、Be、Mg等离子注入,用商用炉进行快速热退火,并用扫描微波光电导、C-V曲线及Hall测试等方法研究了注入层激活率的均匀性。结果表明:快速退火的衬底,其低剂量(3～4×10~(12)cm~(-2))的载流子寿命和迁移率以及高剂量(1×10~(-5)cm~(-2))的载流子浓度可以与热退火的相比或优于热退火的结果。用两种退火方法所得到的这些参数的均匀性没有明显的差别。还研究了两种退火方式对注入层中的损伤消除及载流子激活与温度的关系。对于施主注入,微波光电导技术给出的结果分别与背散射和电学测试所得的结果密切相关。     

GaAs中Si~+注入的X射线双晶衍射研究

本文用X射线双晶衍射术,结合摇摆曲线的计算机模拟和电学测量,研究了 180keV Si+注入GaAs(100)样品及其退火过程中的结构变化.结果表明,注入态时Si原子基本上处在基体中的间隙位上,使点阵产生膨胀,在退火过程中逐渐进入替代位,但这一替代过程进行得并不彻底.当剂量高于 1×10~(13)cm~(-2)时,注入态就显著地产生了间隙Si原子进入替代位的过程.当剂量达到 1×10~(15)cm~(-2)时,经 800℃ 0.5 小时的炉退火仍然不能消除离子注入所引起的损伤和应变,大量Si原子留在间隙位上,使激活率难以提高.分析表明,空位和应力在Si原子从间隙位到替代位的过程中起了很大的作用,是GaAs中Si离子注入产生饱和现象的.主要原因.     

Si离子注入GaAs的红外快速退火

研究了适用于GaAs离子注入材料的石墨红外快速热退火方法,对Si~+注入GaAs材料进行950℃,6秒快速退火。从测得的电学特性,DLTS和GaAs MESFET的研究结果表明,红外快速热退火工艺可获得高质量的有源层以及抑制电子陷阱EL2的外扩散。     

砷化镓超高速电路用SI-GaAs材料——Ⅴ.离子注入技术;Ⅵ.介质/接触/栅材料

5.SI—GaAs的离子注入技术 在GaAs IC/工艺中,通常采用有选择的离子注入,在SI-GaAs衬底上,形成有源层、欧姆接触层、电阻层及器件之间的隔离层。 通过控制注入杂质的能量和剂量,来达到控制掺杂的浓度和深度。加速离子的能量在50～500keV的范围,注入离子的剂量一般在10~(11)～10~(17)/cm~2的范围;衬底可以在室温条件下或加热的条件下(<400℃)进行离子注入。     

Be~+注入GaAs掺杂

本文报道了在气体离子源中Be~+束流的引出,比较了Be~+注入GaAs的常规炉子热退火与红外快速退火行为,给出了Be~+注入GaAs和InGaAs形成的pn结特性。实验表明,用Be~+注入化合物半导体可作为制作器件的一种有效方法。     

Beryllium Ion Implantation into GaAs and Pseudomorphic AIGaAs/lnGaAs/GaAs Heterostructure

Implantations of Be, Be + P, Be + F, Be + P +F, BeF and Mg + P into GaAs and AlGaAs/InGaAs/GaAs pseudomorphic heterostructure were evaluated by secondary ion mass spectrometry profilings and electrical resistivity measurements. Rapid thermal annealing causes a strong diffusion of Be when implanted alone. Co-implantation with P prevents both diffusion and degradation of the Gaussian-shape implant distribution and thus improves the semiconductor sheet resistivity. Annealing at 850°C for 10 s for a Be + P co-implant results in a 60% activation efficiency, and lower diffusion and resistivity when compared to single Be, Be + F, Be + F + P, BeF, and Mg + P implanted at the same dose.     

Beryllium and sulfur ion-implanted profiles in gaas

Atomic profiles of ion-implanted Be and S in GaAs have been measured as a function of implant fluence and annealing temperature. Concentration versus depth profiles were ob-tained by means of secondary ion mass spectrometry (SIMS) techniques. Pyrolytically deposited and sputter-coated Si0₂ and Si₃N₄ films were used as encapsulants for the 500 to 900° annealing study. Semi-insulating GaAs was implanted with 200 keV³⁴S⁺ to fluences of 1 × 10¹⁴ and 5₂× 10¹⁴/cm², and 100 keV⁹Be⁺ in the 1 × 10¹³ to 1 × 10¹⁵/cm² fluence range. The S profiles did not change significantly after annealing at 800°C, although there was some skewing after annealing above 600°C. In contrast, the Be profiles showed significant changes and a decrease in the peak concentration for the ≥ 5 × 10^T4/cm² implants after a 700°C anneal. After a 800°C anneal the Be profile was essentially flat with a monotonic decrease from the surface into the implanted re-gion and a 900°C anneal caused a further decrease in the Be concentration. Profiles of Be implants of ≤ 1 × 10¹⁴/cm² did not change significantly after annealing indicating that the higher fluence cases were related to solubility effects. This work supported by the Naval Electronic Systems Command and the Office of Naval Research.     

MeV Si~+注入SI-GaAs的激活能研究

报导不同注量下MeV硅离子注入半绝缘砷化镓衬底的激活能,随注量增加激活能增大。对相同注入条件分别经一步或两步快退火处理样品的电特性进行了比较,认为MeV硅离子注入砷化镓衬底的退火行为可以分为损伤恢复和杂质激活两步,其杂质激活与点缺陷的运动有关。从能量角度分析了两步快退火优于一步快退火的原因。     

SI GaAS中S~+注入的电学特性

本文研究了经常规热退火和快速热退火后SIGaAs中S~+注入的电学特性.热退火后,GaAs中注入S~+的快扩散和再分布不决定于S~+或砷空位V_(AS)的扩散而决定于离子注入增强扩散.使用快速热退火方法能抑制注入S~+在GaAs中的增强扩散,明显减小S~+的再分布,可以获得适合于制造GaAs MESFET器件的薄有源层.     

10keV B~+注入预非晶化Si的剩余缺陷和浅结

<正> 一、问题的提出和实验方法 在低能注入B~+浅结的过程中,沟道效应难以避免。为避免B~+注入的沟道效应,本文采用100keV下5×10~(15)cm~(-2)的Si~(29)注入n-Si<100>进行非晶化处理。继而进行了10keV,1×10~(15)cm~(-2)的B~+注入形成浅结,然后对样品进行快速热退火(RTA)处理,并观察界面缺陷的     

Ion implantation effects on GaAs MESFETs

The effects of ion-implantation on the uniformity and the ultimately achievable performance of GaAs MESFETs are calculated. The results of an extensive study of the profiles of Si, Se, and Be ions implanted into GaAs are incorporated into a combined process and device model for GaAs MESFET technology. Taken into account are the scaling of transconductances with implantation energy, effects of implant profiles and impurities on low-gate-bias transconductances, dopant diffusion during annealing, effects of encapsulant thickness and etch depth on threshold-voltage uniformity, and effects of recoil atoms on threshold voltages for implants through Si₃N₄ and SiO₂ caps     

Co-Implantation and autocompensation in close contact rapid thermal annealing of Si-implanted GaAs:Cr

Close contact rapid thermal annealing of semi-insulating GaAs:Cr implanted with Si, Si + Al, and Si + P has been studied using variable temperature Hall effect measurements and low temperature (4.2K) photoluminescence (PL) spectroscopy. Isochronal (10 sec) and isothermal (1000° C) anneals indicate that As is lost from the surface during close contact annealing at high anneal temperatures and long anneal times. Samples which were implanted with Si alone show maximum activation at an annealing temperature of 900° C, above which activation efficiency decreases. Low temperature Hall and PL measurements indicate that this reduced activation is due to increasing auto-compensation of Si donors by Si acceptors at higher anneal temperatures. However, co-implantation of column V elements can increase the activation of Si implants by reducing Si occupancy of As sites and increasing Si occupancy of Ga sites, and therebyoffset the effects of As loss from the surface. For samples implanted with Si + P, activation increases continuously up to a maximum at an anneal temperature of 1050° C, and both low temperature Hall and PL measurements indicate that autocompensation does not increase in this case as the anneal temperature increases. In contrast, samples implanted with Si + Al show very low activation and very high compensation at all anneal temperatures, as expected. The use of column V co-implants in conjunction with close contact RTA can produce excellent donor activation of Si implanted GaAs.