It's important to start by saying that it wasn't just Superman, which was created by Jerry Siegel and Joe Schuster (both the children of Jewish immigrants) in 1938. Batman (Bob Kane and Bill Finger) was also created by Jewish immigrants' children. And the grandpappy of them all was Stan Lee, the creator of Marvel's Spider-man, X-men, Hulk, and so many others. He was born Stanley Lieber, and his parents were Jewish immigrants from Romania. Even more specifically, they're all Ashkenazi, which means their families were Yiddish-speaking Jewish immigrants from Central/Eastern Europe.

There's lots of interesting theories about why second generation Jewish-Americans (the kids of Jewish immigrants) created superheroes in the early-mid 20th century, but most of them center around the issue of assimilation, as your question suggests.

Just to give a very little bit of background: there was a huge wave of Jewish immigration to the USA that started in the 1880s and continued until the 1920s. Most of them came from Eastern Europe and were fleeing anti-Semitic violence. They primarily spoke Yiddish as their first language, and the vast majority settled in New York City. By the late 1920s, New York was (arguably) the largest Jewish city in the world.

Acceptance into American society didn't come easily to poor immigrants who didn't speak English and who belonged to a religious minority. America was then (and remains) overwhelmingly Protestant. Persecution of Jews was less intense in America at the time than in places like Russia, but it wasn't exactly easy for them to fit in with American society because of their many religious and cultural distinctives (such as eating kosher foods, not working on Shabbat/Saturday, wearing particular clothing, etc.).

For the children of these immigrants, however, assimilation into "mainstream" American society was a key goal. Most grew up speaking Yiddish and English. They often abandoned traditional forms of Jewish culture to adopt more American ways--such as changing the way they dressed, ate, spoke, etc. They tried hard--and largely succeeded--at fitting in. They proved really influential in the creation of new cultural forms that became very popular in America. They helped establish the American comic book industry, the movie industry, and the entertainment industry more broadly, just to name a few. Harry Houdini was Jewish and falls into this category. So was Irving Berlin, the composer of "God Bless America." Ditto for Louis Mayer, founder of MGM studios. It's actually hard to overstate how influential Jewish-American immigrants' children were in forming 20th-century American popular culture.

So, back to Superman. Some argue basically what you're proposing in the question: as the children of immigrants and members of a religious minority group, Superman was like the alter ego of Jewish people trying to fit into America's mostly Protestant Christian society. For those who support this interpretation, Clark Kent is the key figure: Superman has to appear normal and "unassuming" to ordinary Americans, despite having this secret alien power. Like Jewish Americans at the time, Superman struggles to fit into ordinary society.

Others argue that Superman and other superheroes are loosely based on the legends of the Golem, a mythical mud monster that was said to protect Jewish people against their enemies. In this interpretation, the important thing is that Superman is super. He has all these crazy powers, just like the Golem. He protects people without them necessarily knowing that he is protecting them. But his power and protection comes with a great cost: Superman himself can never lead a truly normal life.

So, yes, some historians have looked at this. There's a couple of semi-scholarly books on the subject. One is Arie Kaplan's From Krakow to Krypton (2007). Another is Simcha Weinstein's Up, Up, and Oy Vey (2009). For more scholarly approaches, there's an interesting collection on religion and comics edited by A. David Lewis called Graven Images (2010) that has some relevant articles, and a somewhat crazy (but productively crazy) book by Jeffrey Kripal called Mutants and Mystics (2015) that has a chapter called "Superman is a Crashed Alien." There's a really readable essay in The Oxford Handbook of the Bible in America (2017) that touches on this too: Coates, "The Bible and Graphic Novels/Comics." Also, last but definitely not least, there's a very useful collection of articles edited by Ken Koltun-Fromm called Comics and Sacred Texts (2018) that has some relevant material.

Tl;dr - Superman and other superheroes reflect something very important about second-generation Jewish Americans' efforts to assimilate into 20th-century American society.