It happens that when I write through avrdude the low fuse to 0xe0 (0xe1 by default) then I can not read|write any more in the microcontroller. When I try to read|write, the avrdude show me an error Device signature = 0x000000. The target IC is an atmega8
I am using Arduino as ISP for programming the target board where I use a 16MHz external crystal too. For this reason, I changed the low fuse to use an external crystal but I don't know what's going on.
Setting CKSEL3~0 to 0 selects external clock (ie, an external clock generator, ie a chip which is provided with power and ground and outputs a clock signal on one pin), not an external crystal. Once you do this, the chip can no longer be reprogrammed because a clock source is necessary for programming, and you have selected one that is not present.
For 16MHz crystal, I think you want 0xEF low fuse, and be sure to set CKOPT in high fuse (bit 4, which must be programmed (0).