A mechanism and a reduction technique for large reverse leakage current in p-n junctions

The origin of anomalously large p-n junction leakage current in Si is investigated. The leakage has strong electric field dependence and weak temperature dependence, and therefore cannot be explained by either generation-recombination current or diffusion current. It may be explained by the local Zener effect at local enhancement of the electric field around small precipitates in the depletion layer. Supposing a spherical precipitate, the electric field will be enhanced as much as 1.3 times for a SiO/sub 2/ precipitate and 3 times for a metal precipitate. The leakage features are explained by the electric field dependence and the temperature dependence of the local Zener probability. A new approach to reduce the local Zener probability by controlling the profile of the electric field is proposed, and the validity of the approach is confirmed by direct experiment and by improvement in the refresh operation of DRAM cells. >

[1]  C. Zener.  A theory of the electrical breakdown of solid dielectrics , 1934 .

[2]  C. Kittel.  Introduction to solid state physics , 1954 .

[3]  W. Shockley,et al.  Metal Precipitates in Silicon p‐n Junctions , 1960 .

[4]  W. Shockley.  Problems related to p-n junctions in silicon , 1961 .

[5]  S. Sze,et al.  AVALANCHE BREAKDOWN VOLTAGES OF ABRUPT AND LINEARLY GRADED p‐n JUNCTIONS IN Ge, Si, GaAs, AND GaP , 1966 .

[6]  C. J. Kircher.  Comparison of leakage currents in ion‐implanted and diffused p‐n junctions , 1975 .

[7]  Y. H. Lee,et al.  Near-surface damage and contamination after CF/sub 4//H/sub 2/ reactive ion etching of Si , 1985 .

[8]  J. P. Gowers,et al.  Defects and leakage currents in BF2‐implanted preamorphized silicon , 1986 .

[9]  Reverse-Bias Current Reduction in Low-Temperature-Annealed pn Junctions Using a UHV Ion-Implanter , 1989 .

[10]  Proximity Gettering of Micro-Defects by High Energy Ion Implantation , 1991 .

[11]  Atsushi Hiraiwa,et al.  Local Zener Phenomenon--A Mechanism of p-n Junction Leakage Current-- , 1992 .

[12]  Effects of Various Pre‐Intrinsic and Phosphorus Diffusion Gettering Treatments Upon Quality of Czochralski Silicon Wafer Surface during a Simulated 4 Megabit Dynamic Random Access Memory Process , 1992 .

[13]  W. Wijaranakula.  Morphology of oxide precipitates in Czochralski silicon degenerately doped with boron , 1992 .

[14]  Improvement to Bulk Oxygen Precipitate Density Necessary for Internal Gettering in Antimony Doped N/N+ Epitaxial Wafers Using the 3‐Step Technique and Ramped Nucleation , 1992 .

[15]  F. Shimura,et al.  Hydrogen enhanced out‐diffusion of oxygen in Czochralski silicon , 1993 .

[16]  Proximity Gettering of Heavy Metals by High-Energy Ion Implantation , 1993 .