Cu(Mg) alloy의 표면과 계면에서 형성된 MgO의 확산방지능력 및 표면에 형성된 MgO의 전기적 특성 연구

조홍렬; 조범석; 이재갑; Heunglyul Cho; Beonseok Cho; Jaegab Lee

Korean Journal of Materials Research, Vol.10, No.2, 160-165, February, 2000

A study on Electrical and Diffusion Barrier Properties of MgO Formed on Surface as well as at the Interface Between Cu(Mg) Alloy and SiO 2

조홍렬, 조범석, 이재갑

국민대학교 금속재료공학부

Heunglyul Cho, Beonseok Cho, and Jaegab Lee

School of Metallurgical and Material Engineering, Kookmin University, 861-1, Chongnung-dong, Songbuk-gu, Seoul, 136-702, Korea

초록

Sputter Cu(1-4.5at.%Mg) alloy를 100mTorr이하의 산소압력에서 온도를 증가시키며 열처리하였을 때 표연과 계면에서 형성된 MgO의 확산방지막 특성을 살펴보았다 먼저, Cu(Mg)/SiO 2 /Si 구조의 샘플을 열처리했을 때 계면에서는 2Mg+SiO 2 →2MgO+Si 의 화학반응에 의해 MgO가 형성되는데 이 MgO충에 의해 Cu가 SiO 2 로 확산되는 것이 현저하게 감소하였다. TiN/Si 기판 위에서도 Cu(Mg)과 TiN 계면에 MgO가 형성되어 Cu(4.5at.%Mg)의 경우 800 ? C 까지 Cu와 Si의 확산을 방지할 수 있었다. 표면에 형성된 MgO위에 Si을 증착하여 Si/MgO(150\AA)/Cu(Mg)/SiO 2 /Si 구조로 만든 후 열처리했을 때 150\AA 의 MgO는 700 ? C 까지 Si과 Cu의 확산을 방지할 수 있었다. 표면에 형성된 MgO( 150\AA )의 누설전류특성은 break down 5V, 누설전류 10 ?7 A/cm 2 의 값을 나타냈다. 또한 Si 3 N 4 /MgO 이중구조에서는 매우 낮은 누설전류밀도를 나타냈으며 MgO에 의해 Si 3 N 4 증착시 안정적인 계면이 형성됨을 확인하였다.

We have investigated the electrical and diffusion barrier properties of MgO produced on the surface of Cu (Mg) alloy. Also the diffusion barrier property of the interfacial MgO between Cu alloy and SiO 2 has been examined. The results show that the 150\AA -MgO layer on the surface remains stable up to 700 ? C , preventing the interdiffusion of C Cu and Si in Si/MgO/Cu(Mg) structure. It also has the breakdown voltage of 4.5V and leakage current density of 10 ?7 A/cm 2 / . In addition, the combined structure of Si 3 N4(100\AA)/MgO(100\AA) increases the breakdown voltage up to lOV and reduces the leakage current density to 8\tiems10 ?7 A/cm 2 . Furthermore, the interfacial MgO formed by the chemical react tion of Mg and SiO 2 reduces the diffusion of copper into SiO 2 substrate. Consequently, Cu(Mg) alloy can be applied as a g gate electrode in TFT /LCDs, reducing the process steps.

Keywords:Cu(Mg) alloy;MgO;Diffusion barrier;Electrical property

[References]

Edelstein D, Heidenreich J, Goldblatt R, Cote W, Uzoh C, Lustig N, Roper P, McDevitt T, Motsiff W, Simon A, Dukovic J, Wachnik R, Rathore H, Schulz R, Su L, Luce S, Slattery J, International Electron Devices Meetihg, 773 (1997)
Andricacos PC, INTERFACE, 8(1) (1999)
Gilbert P, Yang I, Pettinato C, Angyal M, Boeck B, Fu C, VanGompel T, Tiwari R, Sparks T, Clark W, Dang C, Mendonca J, Chu B, Lucas K, Kling M, Roman B, Park E, Huang F, Woods M, Rose D, McGuffin K, Nghiem A, Banks E, McNelly T, Feng C, Sturtevant J, De H, International Electron Devices Meeting, 1013 (1998)
Ding PJ, Lanford WA, Hymes S, Muraka SP, Appl. Phys. Lett., 64(21), 2897 (1994)
Lanford WA, Ding PJ, Wang W, Hymes S, Muraka SP, Thin Solid Films, 262, 234 (1995)
Ding PJ, Lanford WA, Hymes S, Muraka SP, J. Appl. Phys., 75(3627) (1994)
Li J, Mayer JW, Colgan EG, J. Appl. Phys., 70(5), 2820 (1991)
Sirringhaus H, Theiss SD, Kahn A, Wagner S, IEEE, 18(8), 388 (1997)

[Related Articles]

[1] Edelstein D, Heidenreich J, Goldblatt R, Cote W, Uzoh C, Lustig N, Roper P, McDevitt T, Motsiff W, Simon A, Dukovic J, Wachnik R, Rathore H, Schulz R, Su L, Luce S, Slattery J, International Electron Devices Meetihg, 773 (1997)

[2] Andricacos PC, INTERFACE, 8(1) (1999)

[3] Gilbert P, Yang I, Pettinato C, Angyal M, Boeck B, Fu C, VanGompel T, Tiwari R, Sparks T, Clark W, Dang C, Mendonca J, Chu B, Lucas K, Kling M, Roman B, Park E, Huang F, Woods M, Rose D, McGuffin K, Nghiem A, Banks E, McNelly T, Feng C, Sturtevant J, De H, International Electron Devices Meeting, 1013 (1998)

[4] Ding PJ, Lanford WA, Hymes S, Muraka SP, Appl. Phys. Lett., 64(21), 2897 (1994)

[5] Lanford WA, Ding PJ, Wang W, Hymes S, Muraka SP, Thin Solid Films, 262, 234 (1995)

[6] Ding PJ, Lanford WA, Hymes S, Muraka SP, J. Appl. Phys., 75(3627) (1994)

[7] Li J, Mayer JW, Colgan EG, J. Appl. Phys., 70(5), 2820 (1991)

[8] Sirringhaus H, Theiss SD, Kahn A, Wagner S, IEEE, 18(8), 388 (1997)