低噪聲非晶硅鍺合金薄膜電學(xué)性能研究
發(fā)布時(shí)間：2018-10-07 20:57
【摘要】：非制冷紅外焦平面探測(cè)器在軍用和民用領(lǐng)域得到了廣泛應(yīng)用，而具有自主知識(shí)產(chǎn)權(quán)的小尺寸、長(zhǎng)壽命和高性能的非制冷紅外焦平面探測(cè)器，是我國(guó)高科技領(lǐng)域的迫切需求。其中，深入探索和研究具有優(yōu)異電學(xué)性能的低噪聲紅外敏感薄膜，意義重大。氫化硅鍺合金薄膜因具有更高的光吸收效率（鍺的吸收系數(shù)比硅高出1～2個(gè)數(shù)量級(jí)）、更低的電阻率和更佳的電學(xué)性能，而在紅外成像傳感器領(lǐng)域有著良好的應(yīng)用前景而備受關(guān)注。此外，采用等離子體增強(qiáng)化學(xué)氣相沉積技術(shù)（PECVD）制備氫化硅鍺合金薄膜，工藝成熟穩(wěn)定，與硅半導(dǎo)體工藝的兼容性良好，便于工業(yè)應(yīng)用。 薄膜噪聲測(cè)試目前仍存在有很多不確定性因素，本文簡(jiǎn)要闡述了薄膜噪聲產(chǎn)生的機(jī)理和物理模型，以便確定薄膜噪聲的測(cè)試方案。為了能夠系統(tǒng)地評(píng)價(jià)薄膜的噪聲水平，自行搭建了一個(gè)薄膜噪聲測(cè)試平臺(tái)，以確保噪聲測(cè)試結(jié)果的可靠性，并建立了統(tǒng)一的評(píng)價(jià)手段。 利用射頻等離子體增強(qiáng)化學(xué)氣相沉積（RF-PECVD）系統(tǒng)裂解硅烷和鍺烷，并輔助以氬氣稀釋，制備氫化硅鍺（Si1-xGex:H）合金薄膜。借助原子力顯微（AFM）、X射線衍射（XRD）、拉曼光譜（Raman）和傅里葉變換紅外光譜（FTIR），分析和研究不同氬稀釋比例下薄膜樣品的結(jié)構(gòu)演變和晶化狀況。研究發(fā)現(xiàn)，在Si1-xGex:H合金薄膜的晶化生長(zhǎng)過程中，氬的引入及其對(duì)硅烷和鍺烷的稀釋發(fā)揮了重要的作用。當(dāng)氬稀釋比例（氬氣與硅烷/鍺烷混合氣比例）相對(duì)較低約為4時(shí)，在非晶網(wǎng)絡(luò)中開始出現(xiàn)納米晶粒。隨著氬稀釋比例的增加，薄膜表面粗糙度、薄膜內(nèi)納米晶粒尺寸、晶化體積比和氫含量均有不同程度的增加。同時(shí)發(fā)現(xiàn)，隨著氬稀釋比例的提高，薄膜的電導(dǎo)率和電阻溫度系數(shù)TCR均有微弱的提高。值得關(guān)注的是，由于氬稀釋在非晶網(wǎng)絡(luò)中引入了納米晶化，薄膜的有序度得到提高，極大地改善了薄膜低噪聲水平。 為了進(jìn)一步提高薄膜的電學(xué)性能水平，，本文還研究了硼摻雜對(duì)氫化微晶硅鍺薄膜的影響。測(cè)試結(jié)果表明，當(dāng)硼摻雜比例為1%時(shí)，薄膜在室溫下有較高的電導(dǎo)率（≥10~(-2)S/m）和較高的TCR（≥3%/K），薄膜噪聲處于較低的水平。
[Abstract]:Uncooled infrared focal plane detectors have been widely used in military and civil fields. The uncooled infrared focal plane detectors with small size, long life and high performance, which have independent intellectual property rights, are the urgent needs in the field of high technology in China. Among them, it is of great significance to explore and study low noise infrared sensitive thin films with excellent electrical properties. Because of its higher optical absorption efficiency (the absorption coefficient of GE is 1 ~ 2 orders of magnitude higher than that of Si), the film has lower resistivity and better electrical properties. In the field of infrared imaging sensors, it has a good application prospect and has attracted much attention. In addition, SiGe alloy films prepared by plasma enhanced chemical vapor deposition (PECVD) technology are mature and stable, and have good compatibility with silicon semiconductor process, which is convenient for industrial application. There are still many uncertain factors in the measurement of thin film noise. In this paper, the mechanism and physical model of film noise are briefly described in order to determine the measurement scheme of film noise. In order to evaluate the noise level of thin films systematically, a film noise testing platform is set up to ensure the reliability of the noise test results, and a unified evaluation method is established. Silicon germanium hydride (Si1-xGex:H) alloy thin films were prepared by radiofrequency plasma enhanced chemical vapor deposition (RF-PECVD) system. The structure evolution and crystallization of films with different argon dilution ratios were studied by atomic force microscopy (AFM) X-ray diffraction (XRD), Raman spectroscopy (Raman) and Fourier transform infrared spectroscopy (FTIR),). It is found that the introduction of argon and its dilution of silane and germanium play an important role in the crystallization and growth of Si1-xGex:H alloy films. When the ratio of argon dilution (ar / silane / germanium mixture) is about 4, nanocrystalline grains begin to appear in the amorphous network. With the increase of argon dilution ratio, the surface roughness, nanocrystalline size, crystallization volume ratio and hydrogen content increase in varying degrees. It was also found that the conductivity and the resistance temperature coefficient (TCR) of the films increased slightly with the increase of the argon dilution ratio. It is worth paying attention to that the order degree of the films is improved and the low noise level of the films is greatly improved because of the introduction of nanocrystalline crystallization in the amorphous network by argon dilution. In order to further improve the electrical properties of the films, the effect of boron doping on hydrogenated microcrystalline silicon germanium films was also studied. The results show that when boron doping ratio is 1, the film has high conductivity (鈮
本文編號(hào)：2255645
[Abstract]:Uncooled infrared focal plane detectors have been widely used in military and civil fields. The uncooled infrared focal plane detectors with small size, long life and high performance, which have independent intellectual property rights, are the urgent needs in the field of high technology in China. Among them, it is of great significance to explore and study low noise infrared sensitive thin films with excellent electrical properties. Because of its higher optical absorption efficiency (the absorption coefficient of GE is 1 ~ 2 orders of magnitude higher than that of Si), the film has lower resistivity and better electrical properties. In the field of infrared imaging sensors, it has a good application prospect and has attracted much attention. In addition, SiGe alloy films prepared by plasma enhanced chemical vapor deposition (PECVD) technology are mature and stable, and have good compatibility with silicon semiconductor process, which is convenient for industrial application. There are still many uncertain factors in the measurement of thin film noise. In this paper, the mechanism and physical model of film noise are briefly described in order to determine the measurement scheme of film noise. In order to evaluate the noise level of thin films systematically, a film noise testing platform is set up to ensure the reliability of the noise test results, and a unified evaluation method is established. Silicon germanium hydride (Si1-xGex:H) alloy thin films were prepared by radiofrequency plasma enhanced chemical vapor deposition (RF-PECVD) system. The structure evolution and crystallization of films with different argon dilution ratios were studied by atomic force microscopy (AFM) X-ray diffraction (XRD), Raman spectroscopy (Raman) and Fourier transform infrared spectroscopy (FTIR),). It is found that the introduction of argon and its dilution of silane and germanium play an important role in the crystallization and growth of Si1-xGex:H alloy films. When the ratio of argon dilution (ar / silane / germanium mixture) is about 4, nanocrystalline grains begin to appear in the amorphous network. With the increase of argon dilution ratio, the surface roughness, nanocrystalline size, crystallization volume ratio and hydrogen content increase in varying degrees. It was also found that the conductivity and the resistance temperature coefficient (TCR) of the films increased slightly with the increase of the argon dilution ratio. It is worth paying attention to that the order degree of the films is improved and the low noise level of the films is greatly improved because of the introduction of nanocrystalline crystallization in the amorphous network by argon dilution. In order to further improve the electrical properties of the films, the effect of boron doping on hydrogenated microcrystalline silicon germanium films was also studied. The results show that when boron doping ratio is 1, the film has high conductivity (鈮
本文編號(hào)：2255645
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