I have looked at the best colleges for STEM subjects that prioritise female applicants. I found three that may be of particular interest.
Universities ranking highly in STEM subjects and that are actively recruiting women:
At 48 schools, women were admitted at a higher rate than men. The female edge was notable at Massachusetts Institute of Technology (eight percentage points), California Institute of Technology (10 points), Carnegie Mellon University (10 points) and Harvey Mudd College (24 points). At those four schools, men outnumbered women significantly. (https://www.washingtonpost.com/local/education/the-gender-factor-in-college-admissions/2014/03/26/4996e988-b4e6-11e3-8020-b2d790b3c9e1_story.html )
California Institute of Technology
Caltech is one of the best schools for science and engineering in the nation, but it hasn’t ignored diversity in its enrollment to get there. It is home to large numbers of female students and professors alike. Since 2001, the school has gone to great lengths to even out the genders on campus, with the goal of doubling the female faculty over the next decade and making significant increases in the number of female students. (http://www.bestcollegesonline.com/blog/the-10-best-colleges-for-females-in-stem-fields/)
Harvey Mudd College
Dr. Mara Klawe has made it her mission to bring more women into STEM since she became president of Harvey Mudd College. A nationally-recognized computer scientist, mathematician, and educator, there may be no one else better qualified to help inspire women to get into more science, technology, engineering, and mathematics majors, and her methods seem to be working at Harvey Mudd. Since she took over five years ago, the percentage of students who are female has risen from 33% to 42% and the numbers of women in computer science have jumped from 10% to 40%. Other majors have had big increases as well, with 37% of engineering majors and 20% of physics majors being female, majors that are traditionally extremely male-dominated. (http://www.bestcollegesonline.com/blog/the-10-best-colleges-for-females-in-stem-fields/)
In 2014 it was ranked number 1 for engineering. (https://www.hmc.edu/about-hmc/2014/09/11/u-s-news-payscale-rankings/
Carnegie Mellon University
Carnegie Mellon welcomes women who want to pursue a career in a science or technology field. Take the school’s computer science department as an example. In 2005, just 7% of the school’s computer science students were female. Today, more than 40% of the students in the program are female. The change was largely due to changes in the way the school approached potential students, actively recruiting women and modifying admission requirements. (http://www.insidehighered.com/news/2010/03/22/stem)
MIT
It's constantly being referred to as one of the best tech colleges in existence, and what makes it even better is its special focus on helping female STEM students succeed just as well and as often as their male counterparts.
MIT has its very own Women's Initiative program all about women in science, aimed at making future female STEM students feel welcome, appreciated and supported in the field. The Women's Initiative program brings presenters from MIT around the country to reach middle and high school girls before society slams down their STEM dreams—it's a mission that's truly inspirational. (http://www.hercampus.com/life/campus-life/steminist-schools)
Women make up nearly half of MIT's undergraduate student body and a growing number of its faculty and leaders, including MIT's former President, Susan Hockfield. In 2009-2010, there were 1,916 undergraduate women and 1,916 graduate women studying at MIT, and 213 female faculty.
...In the past 30 years, as society finally began to see that math, science and engineering weren't "just for boys" anymore, MIT has enrolled a skyrocketing number of women students. Gifted young women with a passion for technical subjects have found in MIT an extremely collaborative and supportive educational environment - and they have made it even stronger and more dynamic. (http://wiki.mitadmissions.org/Women_at_MIT)