Have you read this article ?

It's difficult to summarise this problem, as all of Pacman's mazes were (presumably) manually created. However, you could reduce the problem down to existing ones. I'm not entirely sure how convincing the results might be, but you could, in theory, create the maze automatically.

Pacman, as a game, requires that there is a central box that only the ghosts may enter. Your maze-generation algorithm may not touch this. Also, Pacman himself must start on a clear horizontal path just below this box. Furthermore, we require that each quadrant has its own power-pill and that every walkable square, including those containing the power-pills, are accessible from everywhere else in the maze.

So we need to create the central box, the start point, and the power pills, then let the algorithm 'mazify' the remainder of the map, without creating any disconnected components. Kruskal or Prim's algorithm can do this: we create the default parts of the map, randomly generate more walls to fill in the rest of the map (excluding the ghost-box interior and the power-pill spawn points), then use a spanning-tree generating algorithm to cut holes so that everywhere is accessible.

I leave the details to you, but I'd like to see how your results turn out.

Admiral