Title :
A new test structure for the evaluation of graft-base lateral diffusion depth in high-performance bipolar transistors
Author :
Tamaki, Yoichi ; Shiba, Takeo ; Kure, Tokuo ; Nakamura, Tohru
Author_Institution :
Device Dev. Center, Hitachi Ltd., Tokyo, Japan
fDate :
8/1/1994 12:00:00 AM
Abstract :
A new test structure allows the first electrical measurement of lateral diffusion depth of the graft base in high-performance bipolar transistors. It is indispensable for realizing high cutoff frequency to control the graft-base depth. The test structure has two independent base electrodes and no emitter region. It can evaluate the effective intrinsic-base length by measuring resistance between two electrodes. Graft-base depth can be derived from the active-base length and the effective intrinsic-base width. The feasibility of this structure Is confirmed by evaluating 50-GHz and 30-GHz transistors, with graft-base depths of 0.05 μm and 0.13 μm, respectively. The new method is compared with conventional ones
Keywords :
bipolar transistors; heavily doped semiconductors; semiconductor device testing; 0.05 micron; 0.13 micron; 30 GHz; 50 GHz; active-base length; cutoff frequency; effective intrinsic-base length; effective intrinsic-base width; electrical measurement; graft-base lateral diffusion depth; high-performance bipolar transistors; independent base electrodes; test structure; Bipolar transistors; Bismuth; Boron; Cutoff frequency; Electrodes; Etching; Ion implantation; Parasitic capacitance; Scanning electron microscopy; Testing;
Journal_Title :
Semiconductor Manufacturing, IEEE Transactions on
