If you need the eggs raw, you could submerge them in boiling water for 5 sec. That would kill any bacteria on the shell and the egg would still be raw inside. Put the eggs in cold water right away to prevent the egg from heating up by the residual heat in the shell. I have tried this many times and the eggs do not cook.
If you are serving the eggs to very young children, pregnant women or someone who are sick, you should buy pasteurized eggs instead. But normally it's safer to eat eggs from chickens you raise, than the ones from a factory, because they are more healthy and their immune system is well developed enough to kill the salmonella itself.
There is probably still some risk, so I wouldn't assume it was safe; however, ice-cream is frozen, so I wouldn't worry about ice-cream at all, unless the egg-mixture was left at room temperature for a significant time before freezing.
As far as I know, salmonella is in the faeces of the chicken, if present. Some faeces will often stick to the shell. In very rare circumstances, which I believe are negligible, the salmonella penetrates the shell and infects not only the white (less of a problem) but also the nutritious yolk, and then the whole egg is contaminated. But this chance is probably too small to encounter in one's average life time.
What has normally happened if the faeces are contaminated and people get sick, is that some of the salmonella present on the outside of the shell contaminates the egg when the shell is broken, or the extremely small number of bacteria present in the white get a chance to infect the whole egg (chance ca. 0.005 %, see below). (Note that in many countries the outside of the shell of supermarket eggs is supposedly sterilized.) At that very moment, however, the number of bacteria present in the egg white should still not be enough to make people sick. But if the egg is then left to sit outside the refrigerator for several hours, and enough faeces touched the egg white, the bacteria may have enough time to multiply and make you sick. If the egg is properly refrigerated, chances are much lower, but I do not know the exact numbers.
One often sees grey spots and smears on the outside of eggs; I believe this is normally chicken faeces. Even so, salmonella is quite rare, such that the healthy shouldn't be worried about making ice cream, mousse au chocolat, and such from unpasteurized eggs. But if a young child, an old person, a pregnant woman, or someone with health problems were to eat the ice cream, I would not take the chance and use pasteurized eggs. If the food is contaminated, the fact that people do not get sick who have eaten it immediately upon making it offers little evidence, because the bacteria haven't had the time to multiply yet. I believe you will normally not get sick from eating contaminated steak tartare, for example, because it is eaten immediately.
However that may be, ice-cream is frozen: as Derobert said below, salmonella probably cannot multiply below 5 °C, and certainly not below 0 °C, so ice-cream should be safe under all normal circumstances, that is, if it was frozen shortly after breaking the eggs. Normal temperatures in refrigerators slow down the growth of the bacteria as well: perhaps you shouldn't worry too much about anything that is kept at 7 °C anyway for a few days.
The inside of an egg was once considered almost sterile. But, over recent years, the bacterium Salmonella enteritidis (Se) has been found inside a small number of eggs. Scientists estimate that, on average across the U.S., only 1 of every 20,000 eggs might contain the bacteria. So, the likelihood that an egg might contain Se is extremely small – 0.005% (five one-thousandths of one percent). At this rate, if you’re an average consumer, you might encounter a contaminated egg once every 84 years. — The Incredible Egg, Medicine Net
Best Answer
One alternative is to use pasteurized eggs.