InAs/GaSb Ⅱ类超晶格台面的ICP刻蚀研究
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摘要
报道了采用Cl_2/N_2电感耦合等离子(ICP)组合体刻蚀工艺在InAs/GaSb Ⅱ类超晶格红外焦平面台面加工过程中的研究结果,实验采用分子束外延技术在GaSb衬底上生长的PIN型超晶格材料。结果表明,气体流量比例直接对刻蚀速率和刻蚀形貌产生影响,氯气含量越高,刻蚀速率越大,当氮气含量增加,刻蚀速率降低并趋于一定值。当氯气和氮气的流量比例和等离子腔体内压力等参数一定时,随着温度升高,刻蚀速率和选择比在有限范围内同时线性增大,台面的倾角趋于直角,台面轮廓层状纹理逐渐消失,但沟道内变得粗糙不平,并出现坑点。在实验研究范围内,电感耦合等离子源的ICP功率和RF功率对刻蚀结果产生的影响较小。
The results of a Cl_2/N_2 inductively coupled plasma( ICP) reactive ion etching process on InAs/GaSb superlattices infrared focal plane arrays were reported. A standard PIN device structure based on GaSb substrate was applied in all samples grown by molecular beam epitaxy. The etching results including etching rate and mesa sidewall profile were affected by gas flowratios directly,The higher the chlorine content was,the higher the etching rate was. When the nitrogen content increases,the etching rate decreases and tends to a certain value. When other parameters such as chamber pressure et al. were fixed,the etching rate and selection ratio increased linearly with temperature increasing.The mesa tended to be right angle,and the layered texture profile gradually disappeared,while the channel became rough and even pitted. Within the scope of this study,ICP and RF power had little effect on the etching results.
The results of a Cl_2/N_2 inductively coupled plasma( ICP) reactive ion etching process on InAs/GaSb superlattices infrared focal plane arrays were reported. A standard PIN device structure based on GaSb substrate was applied in all samples grown by molecular beam epitaxy. The etching results including etching rate and mesa sidewall profile were affected by gas flowratios directly,The higher the chlorine content was,the higher the etching rate was. When the nitrogen content increases,the etching rate decreases and tends to a certain value. When other parameters such as chamber pressure et al. were fixed,the etching rate and selection ratio increased linearly with temperature increasing.The mesa tended to be right angle,and the layered texture profile gradually disappeared,while the channel became rough and even pitted. Within the scope of this study,ICP and RF power had little effect on the etching results.
引文
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[4]Nguyen J,Hill C J,Rafol D,et al. Pixel isolation of low dark-current large-format In As/Ga Sb superlattice complementary barrier infrared detector focal plane arrays with high fill factor[J]. SPIE,2011,7945:79451.
[5]ZHANG Guo-Dong,SI Jun-Jie,WANG Li-Wen,et al. High rate etching of In Sb in high density plasma of CH4/H2/Ar and Cl2[J]. Infrared Laser Eng,(张国栋,司俊杰,王理文,等.利用CH4/H2/Ar及Cl2高密度等离子体对In Sb的高速率刻蚀研究.红外与激光工程)2012,41(4):843-846.
[6]ZHANG Li-Xue,SUN Wei-Guo,LYU Yan-Qiu,et al. Mesa etching of type II In As/Ga Sb superlattice[J]. J Infrared Millim. Waves,(张利学,孙维国,吕衍秋,等. In As/Ga SbⅡ类超晶格材料台面腐蚀.红外与毫米波学报)2014,33(5):472-476.
[7]Donnelly V M,Flamm D L,Tu C W,et al. Temperaturedependence of In P and Ga As etching in a chlorine plasma[J]. J. Electrochem. Soc,1982,129:2533-2537.
[8]Lee J W,Lim W T,Baek I K,et al. Etching of As-and Pbased III-V semiconductors planar inductively coupled BCl3/Ar plasma[J]. J Electron Mater,2004,33(4):358-363.
[2]Smith D L,Maihiot C. Proposal for strained type II superlattice infrared detectors[J]. J Appl Phys,1987,62(6):2545-2548.
[3]Giehl A R,Gumbel M,Kessler M,et al. Deep dry etching of Ga As and Ga Sb using Cl2/Ar plasma discharges[J].Vac Sci Technol B,2003,21:2393-2397.
[4]Nguyen J,Hill C J,Rafol D,et al. Pixel isolation of low dark-current large-format In As/Ga Sb superlattice complementary barrier infrared detector focal plane arrays with high fill factor[J]. SPIE,2011,7945:79451.
[5]ZHANG Guo-Dong,SI Jun-Jie,WANG Li-Wen,et al. High rate etching of In Sb in high density plasma of CH4/H2/Ar and Cl2[J]. Infrared Laser Eng,(张国栋,司俊杰,王理文,等.利用CH4/H2/Ar及Cl2高密度等离子体对In Sb的高速率刻蚀研究.红外与激光工程)2012,41(4):843-846.
[6]ZHANG Li-Xue,SUN Wei-Guo,LYU Yan-Qiu,et al. Mesa etching of type II In As/Ga Sb superlattice[J]. J Infrared Millim. Waves,(张利学,孙维国,吕衍秋,等. In As/Ga SbⅡ类超晶格材料台面腐蚀.红外与毫米波学报)2014,33(5):472-476.
[7]Donnelly V M,Flamm D L,Tu C W,et al. Temperaturedependence of In P and Ga As etching in a chlorine plasma[J]. J. Electrochem. Soc,1982,129:2533-2537.
[8]Lee J W,Lim W T,Baek I K,et al. Etching of As-and Pbased III-V semiconductors planar inductively coupled BCl3/Ar plasma[J]. J Electron Mater,2004,33(4):358-363.