When our species has become extinct, is there anything that would survive long enough to tell the next intelligent species to arise that we were a technological civilization?

Almost certainly, depending on the time scale. Physical constructs will eventually break down, but the impact on the environment in total will likely be able to be deduced for millions of years.

For example, we already have a good record of the five previous mass extinction events, and can tie them directly to geological causes. On our current trajectory, a sixth wouldn't necessarily tie well to any other factors other than the activity of a dominant species. This is one of many factors in the proposed geological epoch of the anthropocene.