Tiffany,

Congratulations on your graduation.

I recommend searching "phd" to find many threads here in which many of your questions are addressed.  That's a good way to begin this process.

I'll keep my comments brief here, because I have a big stack of exams to grade.

1)  In the US, a master's will take another two years of your life.  Double or triple (or even quadruple) that for a PhD by the time the dissertation is done and filed.  If you stop to think about it, it's a profound difference in just that aspect alone.

2)  My standard advice to students in your quandary is this: think about what you really want to do professionally over the next 10 to 20 years.  What excites you?  How do you want to spend your workdays?  What's the ideal job description for you?  Now, ask this: must I have a PhD to get that job?  (Many/most full-time academic positions fit this category.)  If the answer is yes, then look into the doctorate.  But often the answer is no.  For many design-related jobs--interesting, fulfilling, creative ones--a second masters in a related, complementary field would give you a real competitive advantage over your competitors in a fraction of the time. 

Of course, doctoral education is a great thing, too.  My point isn't to discourage, but to point out some of the challenges as well as viable alternatives.

Good luck!

Thank you very much for answering! It was very enlighting.

The truth is that at this point in my life, an academic career sounds really exciting and interesting to me. I will keep looking.

Thank you again, very much, for your advice!

One must also note that if seeking employment in architecture is very challenging right now, seeking employment in higher education in architecture (really depends on your specialization...) may be a few times harder than that due to the various cut-backs in this sector that usually take a longer time to manifest itself. You should consider this aspect very seriously if you are do not have another source of income.