Hello, Thanks a lot. but it does not help. I increased the simulation region to a dimension of 0.54 um x 0.54 um. and the heat profile always shows the same x- and y ranges. The monitor_1 size was 5um x 5 um. See the images below:

Though I can't change the X- and Y- range in any way, I can change the Z-ranges by simply tuning the monitor_1 size.
I would appreciate it if you could help me in this regard.