Do CMOS sensors wear out?

Strange question yes I know, as it is solid state but here is why I ask.

I have got a 20D which I have now had for three years, it has shot approximately 47500 images, and has been used in some quite rough conditions, it is physically showing signs of wear (polished corners etc) but I wouldn't think the electronics would wear out however I have noticed an increase in the noise levels of images taken of recent, including images at ISO100 (I never used to see noise at ISO100). Nothing special about the shots (no really long shutter speeds), all converted with DPP.

Any thoughts?

And no I am not looking for an excuse to upgrade!

I have a P & S doing that. It's getting worse over time.

The answer is yes, the why and how fast are complicated.

Based on some quick research and some stuff I used to work with..

You are most likely to see degredation in the first few months of operation or basically not in your lifetime. One estimate I read said it was likely to last over 300 years before failure. Of course you may lose one or two pixels from time to time, but we are talking over decades here.

The exception is if you are in a toxic environment for the sensor (salt air, high-humidity, heavy pollutants, lots of dust ) . Although the odds are other parts of the camera will fail first. Most likely failure of the camera (after the flash card and battery) is the shutter. I got the impression you would likely replace the shutter several times before the sensor went from normal use.

All I can confirm however is as far as I know I have observed no pixel degredation on any of my sensors after delivery and I have had them for 7 years (3.1MP), 5 Years (6.3MP) and 3 Years (16.7MP). But I do note that I have 2 hot green pixels and about 6 out of parameter red pixels (shows at high ISO only) when I got my 16.7MP camera, but have noted no further bad pixels.

Hope that helps,

Thanks Longwatcher. It has been exposed to quite high levels of humidity (its warm and rains a lot down here) and heat (has been left in a hot car on several occasions, on one particular occasion it was almost too hot to pick up!)

Of course you have never gotten it wet either Pete:

Moppie wrote in post #4471749
Of course you have never gotten it wet either Pete:

Sounds like you need a 5D for X-mass

Ah yes add water to that harsh condition list

I would think that leaving it in a hot car could possibly cause some trouble. I have no evidence or technical knowledge to make this more than just a guess though.

All semiconductor materials "wear out" or degrade over time due to slow migration of the doping ions. CMOS sensors are semiconductor devices -- the expected life depends a great deal on the type of device and the manufacturing process. In addition, there are numerous other factors that can affect the expected life of a semiconductor. As a rough guide, conservative useful life estimates vary from about ten years up to fifty years depending on what the device happens to be. Sometimes latent problems related to manufacturing process aren't discovered for many years and can cause early failure -- one of the most famous was known as the "purple plague" -- it was related to the type of plastic used to encapsulate integrated circuits and seal them from the environment. The problem was that they accelerated degradation between gold and aluminum bonds within the encapsulation material and parts began to fail after about 7 years. Also, there are some semiconductors that are implanted with radioactive ions which means that they will decay over time.