Deposition and Properties of Low‐Pressure Chemical‐Vapor Deposited Polycrystalline Silicon‐Germanium Films
Deposition and Properties of Low‐Pressure Chemical‐Vapor Deposited Polycrystalline Silicon‐Germanium Films
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低压化学气相沉积多晶硅锗薄膜的沉积及性能
DOI：
10.1149/1.2055095
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发表时间：
1994
影响因子：
3.9
通讯作者：
K. Saraswat
中科院分区：
文献类型：
--
作者：
T. King;K. Saraswat
本文描述了在低压化学气相沉积系统中，通过SiL4和GeH4的热解，在SiO_2上沉积非掺杂多晶硅-锗(Poly-Si=Ge=)合金薄膜。沉积的薄膜与标准的湿法清洗槽兼容，它们的形成和图案化是非常可控的过程；因此，它们的应用应该不会给硅基技术带来显著的工艺复杂性。由于多晶膜与非晶膜的转变温度随Ge含量的增加而降低，因此根据Ge含量的不同，Si=Ge=薄膜可以在低至~400℃的温度下以多晶形式沉积。多晶硅=Ge=晶粒为柱状结构，微孪晶密度较低，平均尺寸大于相同温度下沉积的多晶硅薄膜中的晶粒尺寸。Si=Ge=的这些特性使其在三维集成电路和大面积电子技术中成为一种有希望的薄膜晶体管材料，这些技术对热工艺预算的要求有限。多晶硅-锗(PolySiGe)最近被证明在金属氧化物半导体(MOS)技术中是一种良好的多晶硅替代材料。-3重掺杂p型多晶硅=Gex由于其较低的电阻率和可变功函数，是亚微米互补MOS(CMOS)技术中极具吸引力的栅电极材料。用传统的微电子制造技术可以在多晶硅中制备出性能良好的薄膜晶体管(TFT)，而在多晶硅中制备的薄膜晶体管(TFT)的工艺温度要求达到600℃或以上，因此在高密度静态存储器(SRAM)、三维集成电路和大面积电子学等TFT集成电路应用中具有很好的应用前景。
The deposition of undoped polycrystalline silicon-germanium (poly-Si~ _= Ge=) alloy films onto SiO2 by the pyrolysis of Sill4 and GeH4 in a low-pressure chemical vapor deposition system is described. The deposited films are compatible with standard wet-cleaning baths, and their formation and patterning are very controllable processes; therefore, their application should not introduce significant process complexity into silicon-based technologies. Depending upon their Ge content, Si~ _= Ge= films can be deposited in polycrystalline form at temperatures as low as~ 400~ because the transition temperature between polycrystalline and amorphous film deposition decreases with increasing Ge content. Poly-Si~ _= Ge= grains are columnar in structure and have a relatively low density of microtwins, and their average size is larger than that of grains in poly-Si films deposited at the same temperature. These properties of Si~ _= Ge= make it a promising material for thin film transistor applications in three-dimensionally integrated circuits and large-area electronics technologies, which have limited thermal process budget requirements.Polycrystalline silicon-germanium (poly-Si~ _= Ge~) has recently been shown to be a favorable alternative to polycrystalline silicon (poly-Si) for various applications in metal oxide semiconductor (MOS) technologies.-3 Heavily doped p-type poly-Si~ _= Gex is an attractive candidate for the gate-electrode material in submicrometer" complementary MOS (CMOS) technologies, because of its lower resistivity and variable work function. Thin film transistors (TFTs) with well-behaved characteristics can be fabricated in poly-Si~ _= Ge= films using conventional microelectronic fabrication techniques without exceeding 550~ 2 whereas comparable TFTs fabricated in poly-Si require processing temperatures at or above 600~ The significant reductions in process temperature afforded by poly-Sil_= Ge~ make it a promising material for TFT integrated-circuit applications such as high density static memories (SRAMs), three-dimensionally integrated CMOS circuits, and large-area electronics.