Daniel Villarreal, F. Wittel, Anusha Rajan, Phillip Wittel, J. Alcantar-Peña, O. Auciello, E. Obaldía
{"title":"氮流对Si/SiO2/HfO2衬底上氮超晶金刚石(N-UNCD)薄膜生长的影响","authors":"Daniel Villarreal, F. Wittel, Anusha Rajan, Phillip Wittel, J. Alcantar-Peña, O. Auciello, E. Obaldía","doi":"10.1109/IESTEC46403.2019.00023","DOIUrl":null,"url":null,"abstract":"This paper describes initial R&D focused on growing ultrananocrystalline diamond films (N-UNCD) with nitrogen (N) atoms incorporated in grain boundaries chemically reacted with C atoms dangling bonds and providing electrons for electrical conductivity. The N-UNCD films are grown on a thin layer of hafnium dioxide (HfO2), to explore the integration of N-UNCD films with the main gate oxide in current CMOS devices. The HfO2 template layer was grown by atomic layer deposition (ALD) on top of a 300 nm layer of silicon dioxide (SiO2) on a silicon substrate. The N-UNCD films are grown using the hot filament chemical vapor deposition (HFCVD) technique. A mixture of Ar/CH4/H2/N2 gases pass through an array of filaments heated to ~2300 °C to crack the CH4 and N2 molecules into C, CHx (x=1,2,3) and N atoms. The radicals react at the surface to grow the N-UNCD. The N-UNCD film density, morphology, and presence of N atoms, which induce electrical conductivity (resistivity), appears to depend mainly on the N2 flow, thus density of N atoms arrival to the substrate surface in conjunction with the film growth temperature. In previous work it was fond that a carbide layer is form beneath the UNCD for both Si, tungsten (W) and Hf. However, when N is added to the gas flow it reduces the coverage of UNCD over the HfO2 layer but not over the SiO2 layer. Large N2 flows (10-20 standard cubic cm, sccm) result in N-UNCD films with globular non-connected structures, resulting in high resistivities (several MW-cm to open circuit). X-ray Photoelectron Spectroscopy (XPS) analysis revealed the presence of both hafnium carbide (HfC) and hafnium nitride (HfxNy) on the surface of N-UNCD films grown on HfO2. The formation of HfxNy may compete with C for surface binding sites on the HfO2, inhibiting the formation of a HfC layer. There are several candidates of hafnium nitride (Hf3N2, Hf3N4. and HfN). Since the starting substrate material is hafnium(IV) oxide, and there is no oxygen flow during the N-UNCD film growth, the hypothesis is that, with large N2 flow (10-20 sccm), the formation of hafnium(IV) nitride is dominant. Hafnium(IV) nitride has an orthorhombic unit cell while hafnium (IV) carbide has a cubic unit cell structure, similar to diamond. Thus, the presence of Hf3N4 may inhibit diamond growth via a mismatch of unit cells at the interface. On the other hand, a low flow of N2 (6 sccm) combined with low flows of H and Ar, produced, good dense, very low resistivity N-UNCD films.","PeriodicalId":388062,"journal":{"name":"2019 7th International Engineering, Sciences and Technology Conference (IESTEC)","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Effect of Nitrogen Flow on the Growth of Nitrogen Ultrananocrystalline Diamond (N-UNCD) Films on Si/SiO2/HfO2 Substrate\",\"authors\":\"Daniel Villarreal, F. Wittel, Anusha Rajan, Phillip Wittel, J. Alcantar-Peña, O. Auciello, E. Obaldía\",\"doi\":\"10.1109/IESTEC46403.2019.00023\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"This paper describes initial R&D focused on growing ultrananocrystalline diamond films (N-UNCD) with nitrogen (N) atoms incorporated in grain boundaries chemically reacted with C atoms dangling bonds and providing electrons for electrical conductivity. The N-UNCD films are grown on a thin layer of hafnium dioxide (HfO2), to explore the integration of N-UNCD films with the main gate oxide in current CMOS devices. The HfO2 template layer was grown by atomic layer deposition (ALD) on top of a 300 nm layer of silicon dioxide (SiO2) on a silicon substrate. The N-UNCD films are grown using the hot filament chemical vapor deposition (HFCVD) technique. A mixture of Ar/CH4/H2/N2 gases pass through an array of filaments heated to ~2300 °C to crack the CH4 and N2 molecules into C, CHx (x=1,2,3) and N atoms. The radicals react at the surface to grow the N-UNCD. The N-UNCD film density, morphology, and presence of N atoms, which induce electrical conductivity (resistivity), appears to depend mainly on the N2 flow, thus density of N atoms arrival to the substrate surface in conjunction with the film growth temperature. In previous work it was fond that a carbide layer is form beneath the UNCD for both Si, tungsten (W) and Hf. However, when N is added to the gas flow it reduces the coverage of UNCD over the HfO2 layer but not over the SiO2 layer. Large N2 flows (10-20 standard cubic cm, sccm) result in N-UNCD films with globular non-connected structures, resulting in high resistivities (several MW-cm to open circuit). X-ray Photoelectron Spectroscopy (XPS) analysis revealed the presence of both hafnium carbide (HfC) and hafnium nitride (HfxNy) on the surface of N-UNCD films grown on HfO2. The formation of HfxNy may compete with C for surface binding sites on the HfO2, inhibiting the formation of a HfC layer. There are several candidates of hafnium nitride (Hf3N2, Hf3N4. and HfN). Since the starting substrate material is hafnium(IV) oxide, and there is no oxygen flow during the N-UNCD film growth, the hypothesis is that, with large N2 flow (10-20 sccm), the formation of hafnium(IV) nitride is dominant. Hafnium(IV) nitride has an orthorhombic unit cell while hafnium (IV) carbide has a cubic unit cell structure, similar to diamond. Thus, the presence of Hf3N4 may inhibit diamond growth via a mismatch of unit cells at the interface. On the other hand, a low flow of N2 (6 sccm) combined with low flows of H and Ar, produced, good dense, very low resistivity N-UNCD films.\",\"PeriodicalId\":388062,\"journal\":{\"name\":\"2019 7th International Engineering, Sciences and Technology Conference (IESTEC)\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-10-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"2019 7th International Engineering, Sciences and Technology Conference (IESTEC)\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1109/IESTEC46403.2019.00023\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"2019 7th International Engineering, Sciences and Technology Conference (IESTEC)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/IESTEC46403.2019.00023","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Effect of Nitrogen Flow on the Growth of Nitrogen Ultrananocrystalline Diamond (N-UNCD) Films on Si/SiO2/HfO2 Substrate
This paper describes initial R&D focused on growing ultrananocrystalline diamond films (N-UNCD) with nitrogen (N) atoms incorporated in grain boundaries chemically reacted with C atoms dangling bonds and providing electrons for electrical conductivity. The N-UNCD films are grown on a thin layer of hafnium dioxide (HfO2), to explore the integration of N-UNCD films with the main gate oxide in current CMOS devices. The HfO2 template layer was grown by atomic layer deposition (ALD) on top of a 300 nm layer of silicon dioxide (SiO2) on a silicon substrate. The N-UNCD films are grown using the hot filament chemical vapor deposition (HFCVD) technique. A mixture of Ar/CH4/H2/N2 gases pass through an array of filaments heated to ~2300 °C to crack the CH4 and N2 molecules into C, CHx (x=1,2,3) and N atoms. The radicals react at the surface to grow the N-UNCD. The N-UNCD film density, morphology, and presence of N atoms, which induce electrical conductivity (resistivity), appears to depend mainly on the N2 flow, thus density of N atoms arrival to the substrate surface in conjunction with the film growth temperature. In previous work it was fond that a carbide layer is form beneath the UNCD for both Si, tungsten (W) and Hf. However, when N is added to the gas flow it reduces the coverage of UNCD over the HfO2 layer but not over the SiO2 layer. Large N2 flows (10-20 standard cubic cm, sccm) result in N-UNCD films with globular non-connected structures, resulting in high resistivities (several MW-cm to open circuit). X-ray Photoelectron Spectroscopy (XPS) analysis revealed the presence of both hafnium carbide (HfC) and hafnium nitride (HfxNy) on the surface of N-UNCD films grown on HfO2. The formation of HfxNy may compete with C for surface binding sites on the HfO2, inhibiting the formation of a HfC layer. There are several candidates of hafnium nitride (Hf3N2, Hf3N4. and HfN). Since the starting substrate material is hafnium(IV) oxide, and there is no oxygen flow during the N-UNCD film growth, the hypothesis is that, with large N2 flow (10-20 sccm), the formation of hafnium(IV) nitride is dominant. Hafnium(IV) nitride has an orthorhombic unit cell while hafnium (IV) carbide has a cubic unit cell structure, similar to diamond. Thus, the presence of Hf3N4 may inhibit diamond growth via a mismatch of unit cells at the interface. On the other hand, a low flow of N2 (6 sccm) combined with low flows of H and Ar, produced, good dense, very low resistivity N-UNCD films.